1) The Foreseeability Rule

Early in the twentieth century, the courts adopted the directness rule. [Note 127: Re Polemis & Furness Withy & Co.,[1921] 3 K.B. 560 (C.A.).] Under that rule a defendant was liable for all the direct consequences of her negligence. Foreseeability was relevant to culpability (breach and duty) but not to the extent of liability. The directness rule tended to favour plaintiffs. By mid-century, however, directness had fallen into judicial disfavour. It was perceived as being too difficult to interpret and apply. This led to a reassessment of the rule of remoteness by the Privy Council in Overseas Tankship (U.K.) Ltd. v. Morts Dock and Engineering Co. Ltd., The Wagon Mound (No. 1). [Note 128: [1961] A.C. 388 (P.C.) [Wagon Mound No. 1].] In that case, the defendant, who was the charterer of the ship The Wagon Mound, negligently discharged furnace oil into Sydney harbour. Eventually it spread under the plaintiff's wharf where welding equipment was being used by the plaintiff's employees. Molten metal from the welding operations dropped onto and ignited cotton waste floating on the water. This in turn ignited the oil and the plaintiff's wharf was damaged by fire. At trial, the fire was found to be unforeseeable. The Australian courts, however, applied the directness rule and imposed liability on the defendant. In the Privy Council the directness rule was repudiated and the defendant's appeal was allowed. The Court held that the defendant was liable only for the reasonably foreseeable consequences of its negligence. The foreseeablity test was favoured on the grounds of fairness and justice to the defendant, its simplicity of application, and the logic of synthesizing breach, duty, and remoteness under the single concept of foreseeability. After a brief period of indecision the Supreme Court adopted the foreseeability test and it is now well entrenched in Canadian negligence law.

It was not, however, immediately clear how the foreseeability test would be interpreted in the context of remoteness of damage. The judgment in Wagon Mound No. 1 suggested a relatively strict approach. It was, in policy, a pro-defendant decision that treated negligence law as predominantly a loss-shifting system grounded in notions of corrective justice between individuals. This approach was at odds with the emerging pro- plaintiff trends of negligence law that emphasized compensation and loss distribution policies. Today, it is apparent that Wagon Mound No. 1 did not unduly hamper the pro-plaintiff drift of negligence law. In a series of decisions the courts have indicated a desire to promote a broad and robust interpretation of foreseeability in the context of remoteness of damage.

2) The Interpretation of Foreseeability

The courts have used a variety of interpretive techniques and stratagems to apply reasonable foreseeability in a generous manner. In combination, they give a great deal of discretion to the trial judge and permit an extensive responsibility for the consequences of a negligent act.

a) The Mechanics of the Accident

In Wagon Mound No. 1 the Court spoke of the need to establish both foreseeability of damage and foreseeability of the consequences of the accident. This left some uncertainty about what, precisely, had to be foreseen, and, in particular, whether the nature of the accident and the manner in which it occurred must be foreseen. This issue was resolved in Hughes v. Lord Advocate. [Note 129: [1963] A.C. 837 (H.L.).] In that case, employees of the defendant Post Office negligently left a manhole open and unattended while they took a tea break. The manhole had a canvas tent over it and paraffin lamps surrounding it. The plaintiff, a young boy, took one of the lamps and climbed down a ladder to explore the manhole. As he was emerging, he accidently dropped the lamp down the hole where it exploded violently. He fell back into the hole and suffered serious burns. The defendant argued that the explosion, which was caused by the vapourization of some of the paraffin, was entirely unforeseeable and, consequently, the plaintiff's loss was too remote. The House of Lords held that the defendant was liable. It decided that there was no need to establish the foreseeability of the explosion. It was sufficient that the plaintiff had suffered a kind of harm (burns) that was foreseeable. The Court's decision that it was not necessary to foresee the manner in which the accident occurred, the mechanics of the accident, or the precise concatenation of events that led to the accident has contributed significantly to the expansive interpretation of the remoteness rule.

b) The Possibility of Damage

In Wagon Mound No. 1, the Privy Council held that the defendant must foresee that the damage was a probable consequence of the negligent act. Some years later, however, in companion litigation arising out of the same incident, the Privy Council held that foreseeability that the damage was a possibility was sufficient. In Wagon Mound No. 2 [Note 130: Overseas Tankship (U.K.) Ltd. v. Miller Steamship Co. Pty. Ltd., The Wagon Mound (No. 2), [1967] 1 A.C. 617 (P.C.) [Wagon Mound No. 2].] the plaintiff owned a ship that was tied up at the wharf where the fire occurred. It also suffered considerable damage. The evidence adduced at trial, on behalf of the plaintiff shipowner, was different from the first case [Note 131: The difference in the evidence is explained by the rule of contributory negligence in New South Wales at the time of the accident. Contributory negligence was a complete defence to an action in negligence. Consequently, it was not in the interests of the plaintiff in Wagon Mound No. 1 to prove the foreseeability of fire in the circumstances because their employees continued welding after they were aware of the furnace oil below the wharf. This could be construed as contributory negligence, and their claim would fail. They, therefore, relied on the directness rule, a winning formula until they reached the Privy Council. The plaintiff in Wagon Mound No. 2 was not troubled by this issue and was in a position to present a strong case based on expert testimony that ignition of the furnace oil was foreseeable.] and it supported a conclusion that while damage by fire was not probable, it was a possibility that in exceptional circumstances could become an actuality. The risk of fire was low, but it was not so far-fetched as never to occur to the mind of a reasonable person. This was held to be sufficient to satisfy the foreseeability test and liability was imposed. This modification of the foreseeability test to include possible damage encompasses most direct consequences of a negligent act and further dissipates the pro-defendant emphasis of Wagon Mound No. 1.

c) Linkage

A common technique to bridge a substantial gulf between the negligent act and the ultimate damage is to divide the causal sequence into a number of discrete steps each of which is a readily foreseeable consequence of the preceding step. A narrative from step to foreseeable step allows the gulf to be spanned in a persuasive way with apparent fidelity to the foreseeability principle. The technique was used in Assiniboine South School Division No. 3 v. Greater Winnipeg Gas Co. [Note 132: (1971), 21 D.L.R. (3d) 608 (Man. C.A.), aff'd [1973] S.C.R. vi [Assiniboine].] In that case, the defendants' failure to start a snowmobile with reasonable care resulted in fire damage to the plaintiff's school. The risk inherent in the starting procedure was that the snowmobile might take off without its rider to the peril of persons and property in the vicinity. The chain of events that led to the fire was broken down into a series of foreseeable occurrences. They included the foreseeability of impact with a building, foreseeability of gas-riser pipes on buildings in that area of Winnipeg, foreseeability of impact with a gas-riser pipe, foreseeability of the escape of gas from the impact with a pipe, and foreseeability that gas might find its way into the school where it might be ignited by a foreseeable pilot flame in the boiler room. Foreseeability was thereby established and liability was imposed. This technique of building foreseeability on foreseeability is not uncommon in remoteness cases. [Note 133: Perhaps the best example of this process, of which courts do not always appear to be conscious, is Falkenham v. Zwicker (1978), 32 N.S.R. (2d) 199 (S.C.T.D.). The defendant driver on a rural highway was held liable for causing illness to the plaintiff farmer's cows. The links included the defendant's negligent driving; the automobile leaving the highway; the automobile hitting the fence surrounding the plaintiff's farm; the fence being a wire fence; staples being ejected from the damaged wire fence into the farmer's field; cows being in the field; cows ingesting the staples; and the cows becoming ill from hardware disease.]

d) The Demarcation of Damage

Courts seeking to impose a broad responsibility for negligence may also exploit the inherent ambiguity of the term damage. It may be defined broadly or narrowly for the purposes of applying the remoteness rule. The broader the definition, the more likely it is that the damage will be found to be foreseeable. Imagine a circumstance where a plaintiff's drinking supply is polluted by the defendant's negligence. The plaintiff is so traumatized when he discovers this that he has a non-fatal heart attack. The damage that the deceased suffered can be classified as coronary disease, illness, or bodily damage. Clearly, the way the question is framed can influence the answer given. Foreseeability of coronary disease may seem implausible but foreseeability of illness or bodily damage seems more reasonable. Judges are not unaware that the demarcation of damage can influence the outcome of a case.

e) The Elasticity of Foreseeability

In remoteness cases the courts have been particularly adept at exploiting the inherent flexibility of foreseeability. Foreseeability is an undefinable concept that can be construed in as myopic or prophetic a manner as circumstances demand. In remoteness cases, courts are not normally receptive to arguments that the loss was unforeseeable. After all, the plaintiff has proved duty of care, negligence, causation, and damage, and there is an understandable reluctance to dismiss the plaintiff's claim unless there are compelling reasons to do so. [Note 134: See, for example, Trevison v. Springman (1995), [1996] 4 W.W.R. 760, aff'd [1997] B.C.J. No. 2557 (C.A.) (QL). In that case, the defendant's son had a known propensity for breaking and entering and theft of the contents of houses. The defendant negligently failed to prevent her son from gaining access to the key to a neighbour's house that had been entrusted to her. The son not only stole from the house (an entirely foreseeable event), but the following night, he returned to the house and, to cover his tracks, he set it alight. The arson was not, in the Court's opinion, a foreseeable consequence of the defendant's negligence.] In most cases an imposition of liability on the defendant is fair, and foreseeability can accommodate that decision with ease.

The conventional view today is that, through the use of these techniques of construction and modification, the foreseeability rule is no more protective of defendants than the directness rule and, indeed, it may be less protective since foreseeable indirect damage [Note 135: See, for example, Assiniboine, above note 132.] is now within the scope of recovery. The pro-defendant sympathies of Wagon Mound No. 1 have been subverted by a pro-plaintiff judiciary.

3) Special Remoteness Issues

There are some remoteness issues that tend to arise frequently. Cases dealing with these common issues have been categorized under descriptive labels. The advantage of this approach is that common problems are identified, the pertinent policy concerns can be addressed, and a greater consistency of decision making may be achieved. The three categories of cases considered here are the thin-skull cases, cases of intervening acts, and cases involving suicide.

a) The Thin-Skull Rule

The thin-skull rule has played a pivotal role in personal injury litigation since the beginning of the twentieth century. It states that, as long as some physical injury to the plaintiff was foreseeable, the defendant is liable for all the consequences of the injury arising from the plaintiff's unique physical or psychological make-up whether or not those consequences were foreseeable. The consequences of a minor accident may, for example, be unexpectedly severe because the plaintiff suffers from a pre-existing vulnerability or condition such as a thin-skull, particularly brittle bones, or a weak heart. Nevertheless, the defendant must take her victim as she finds him and must compensate him for the full extent of his losses.

Shortly after the decision in Wagon Mound No.1, the thin-skull rule was challenged on the ground that it was inconsistent with the foreseeability test adopted in that case. The issue was resolved in Smith v. Leech Brain & Co. Ltd. [Note 136: [1962] 2 Q.B. 405 (C.A.) [Smith].] The defendant's negligence in that case caused one of its employees to suffer a burn on his lip. The burn became malignant and he died from the cancer some years later. A claim was brought by his family. The Court recognized that the deceased was predisposed to cancer and the burn was a promoting agent. Nevertheless, the Court reaffirmed the thin-skull rule and imposed liability. It was sufficient that the burn was foreseeable. It was not necessary to foresee the cancer or death.

The thin-skull rule can operate harshly on defendants. In Smith, for example, the ultimate consequence of death was grossly disproportionate to the threshold injury. Other relatively minor injuries may lead to chronic pain, they may trigger illnesses such as multiple sclerosis and chronic fatigue syndrome, or they may lead to psychiatric conditions.

In spite of its potentially harsh consequences, however, the rule is well entrenched in Canadian negligence law and there are good policy reasons supporting it. First, it promotes the compensatory goals of negligence law in the field of personal injury and is consistent with the strong protection given to the plaintiff's interest in personal security. Second, it relieves the courts from the unenviable and difficult task of determining the normal and foreseeable consequences of trauma in the context of the uniqueness of individual persons. In this way it contributes to the efficient administration of personal injury litigation.

Some of the harshness of the thin-skull rule is mitigated by the crumbling-skull rule. The former is a rule of liability; the latter relates to the assessment of damages. The general principle of tort damages is that the plaintiff must be returned to the position that she would have been in if the accident had not happened. The defendant, however, is not required to place the plaintiff in a better position than she would have been in. A wrongdoer is liable only for the damage that she has caused. Consequently, if the plaintiff's existing condition (a thin skull) is one that has caused no debilitating effects before the accident and is not likely to cause adverse consequences in the future, full damages for the complete loss are awarded. If the pre-existing condition (a crumbling skull) has, however, produced some debilitating effects prior to the accident or is, independently of the accident, likely to cause some disability in the future, the defendant is not liable for the full extent of the damage. The defendant is liable only for what she has caused and damages are calculated to compensate the plaintiff to the extent that the defendant has worsened the plaintiff's underlying condition. Smith is illustrative. The thin-skull rule was used to impose liability for the employee's death but damages were significantly discounted to recognize the fact that the deceased probably would have died prematurely of cancer in any event.

b) Intervening Acts (Novus Actus Interveniens)

An intervening act is one that arises after the defendant's negligent act and either precipitates or worsens the plaintiff's damage. The intervening act may be a culpable or non-culpable act of a third person or an act of nature. A legally operative intervening act, sometimes called a novus actus interveniens, relieves the defendant of responsibility for the damage precipitated or aggravated by it.

Early in the twentieth century, courts were sympathetic to defendants in these situations and they were not reluctant to protect them when an intervening event arose between the negligent act and the occurrence of the damage. This was particularly so in respect of the intervening culpable acts of third persons. This was often explained on the basis of causation. It was suggested that the intervening act broke the chain of causation between the defendant's act and the plaintiff's damage and it was, therefore, the intervening act, and not the defendant's negligence, that was the "real" or "ultimate" cause of the loss. The issue, however, is not one of cause-in-fact. In these cases, the defendant's act is always a cause-in-fact of the damage. The damage would not have occurred but for the defendant's negligence. The issue is one of remoteness of damage and the potential unfairness of holding the defendant liable when an intervening act triggers or worsens the plaintiff's loss.

Modern courts are not as eager to protect defendants from the consequences of their negligence as they were in the past and they are less likely to regard an intervening act as exculpatory. Since the issue is one of remoteness of damage, it is not surprising that the foreseeability test has been adopted to determine if the defendant is liable for the loss triggered or worsened by the intervening act. If the intervening act was broadly within the scope of the foreseeable risk created by the defendant's negligence, he remains liable for the damage caused by it. This has, to some extent, lessened the importance of the kind of intervening act under consideration. The cases do, however, continue to reflect the old classification to the extent that the more culpable the intervening act is, the more likely it is to be found to be unforeseeable.

The central role of reasonable foreseeability in deciding if an intervening act curtails the defendant's responsibility was confirmed by the Supreme Court in Bradford v. Kanellos. [Note 137: (1973), [1974] S.C.R. 409.] The plaintiff was a customer at the defendant's restaurant. An employee of the defendant negligently caused a minor grease fire on the cooking grill, which triggered the automatic fire extinguisher. The hissing sound of the extinguisher caused an unidentified person to shout that gas was escaping and that an explosion might occur. The customers panicked and in the rush to get out of the restaurant, the plaintiff was knocked down and injured. Martland J., who spoke for the majority of the Court, held that the intervening act was unforeseeable and the defendant was not liable to the plaintiff. In his view, the actions of the third person were hysterical and idiotic and were beyond the contemplation of a reasonable person. Spence J., writing for the minority, agreed that foreseeability was the appropriate test but disagreed with the majority's application of it. In his view, the intervening negligence was a usual and normal human response to the situation that occurred and, in the circumstances, was utterly foreseeable.

The contrasting judgments in Bradford are reflective of the uneven handling of intervening negligent acts. In spite of the decision in Bradford, courts today are much more likely to treat intervening negligence as an opportunity to impose joint and several liability on both wrongdoers than as a reason to protect the initial wrongdoer. To that extent, the judgment of Spence J. may be more reflective of current attitudes than that of Martland J.

Nevertheless, there are circumstances where older, more conservative authorities continue to be influential. A good example is where the plaintiff is initially injured by the defendant's negligence and his injuries are worsened by an intervening act of medical malpractice. In 1941 the Ontario Court of Appeal held, in Mercer v. Gray, [Note 138: [1941] O.R. 127 (Ont. C.A.).] that, unlike medical error or mistake, medical negligence is an intervening act that exonerates the first wrongdoer from responsibility for the loss caused by the attending physician. This not only is unfortunate for plaintiffs, given the difficulty of suing physicians, but it is also difficult to defend on grounds of foreseeability or policy. The case has not, however, been applied when the first tortfeasor is herself a physician, [Note 139: Price v. Milawski (1977), 18 O.R. (2d) 113 (C.A.).] and there are indications that it may soon be reconsidered. [Note 140: See Linden, above note 47 at 377-80; and Klar, above note 41 at 358-59.]

The most difficult cases of intervening acts are those involving the intentional conduct of a third person. Courts are reluctant to hold a defendant liable when the loss is triggered by the deliberate and often criminal act of a third person over whom the defendant has no control. Initially, however, care must be taken to separate those situations where the defendant is under a duty of affirmative action to prevent a third person from inflicting intentional damage on the plaintiff. [Note 141: See Klar, above note 41 at 350-55.]

Duties of affirmative action to prevent third persons from deliberately injuring others arise out of special relationships where the defendant has voluntarily assumed some responsibility for controlling the conduct of another person or preventing damage to third persons. They may be imposed, for example, on the custodians of prisoners who are a threat to other inmates or, if they escape, to members of the public, on the caregivers of mentally ill patients who are a danger to society, on personal bodyguards hired to keep celebrities safe from stalkers or overenthusiastic fans, on the operators of security systems designed to prevent theft, on tradespersons who fail to lock the homes of their customers when they leave in order to prevent theft, and on referees in body-contact sports to prevent violence from breaking out or escalating unduly. In these cases, the defendant is negligent because he has failed in his duty of care to prevent third persons from inflicting injury on the plaintiff. It would make no sense to exonerate the defendant on the ground of an intervening act.

The intervening act cases tend to deal with situations where the defendant's negligence has created an opportunity or occasion for a stranger to carry out intentional and sometimes criminal acts against the plaintiff which are not broadly related to the risk created by the defendant. Consider, for example, a variation on the facts of Bradford. Imagine that when the customers panicked and ran out of the restaurant, one customer seized on the opportunity to steal the plaintiff's abandoned handbag. Should the negligent defendant restaurant owner be held liable for this property loss? The usual answer given by the courts is "no." The thief has taken advantage of an opportunity presented by the defendant's negligence but it is not fair to hold the defendant responsible for a risk so different from that which he created. One situation that arises quite frequently is the liability of an owner of an unlocked motor vehicle for damage caused by the bad driving of a thief who steals the vehicle. An action may be brought against the owner on the grounds that it was negligent not to lock the motor vehicle and that the plaintiff would have suffered no loss but for that negligence. In this situation, there are two culpable intervening acts to contend with, the deliberate act of stealing the vehicle and the negligent driving by the thief. Some courts have approached the issue as one of duty while others have seen the issue as one of remoteness. The former may, indeed, be more technically correct but on either view decisions have been based on foreseeability and the results have been quite consistent. [Note 142: See, for example, Hewson v. Red Deer (City of) (1976), 63 D.L.R. (3d) 168 (Alta. S.C. (T.D.)), rev'd (1983), 146 D.L.R. (3d) 32 (Alta. S.C. (A.D.)); O'Reilly v. C. (1979), 99 D.L.R. (3d) 45 (Man. C.A.); Hollett v. Coca-Cola Ltd. (1980), 37 N.S.R. (2d) 695 (S.C.T.D.); Spagnolo v. Margesson's Sports Ltd. (1983), 41 O.R. (2d) 65 (C.A.); and Werbeniuk v. Maynard, [1994] 7 W.W.R. 704 (Man. Q.B.).] In most cases, the courts have refused to impose liability on the negligent owner of the motor vehicle on the ground that the actions of the thief are not foreseeable. Like most remoteness issues, however, the situation presents a choice between competing policies rather than a demand for a factual conclusion about foreseeability. The current position protecting the defendant owner can be supported on the grounds that it is unfair to hold a defendant liable for the criminal acts of those over whom he has no control, that the owner has assumed no responsibility to protect the plaintiff, that the potential responsibility of the owner may extend to a series of culpable acts by the thief resulting in heavy losses, that the act of negligence is relatively minor, and that the imposition of liability adds further insult to the injury of having one's motor vehicle stolen in the first place. This position is, however, becoming more difficult to defend. Both the deterrent and compensatory objectives of tort law support the imposition of liability on the insured owner of the motor vehicle. Furthermore, there are legislative provisions in most provinces making it an offence to leave a motor vehicle unattended on a highway without first stopping the engine, locking the ignition, and removing the key, [Note 143: See, for example, Manitoba Highway Traffic Act, S.M. 1985-86, c. 3, s. 221(1).] and the rise in juvenile car theft, the increasing amount of damage to person and property caused by juvenile car thieves, the popularity of the "club" security device, and the strenuous efforts of the manufacturers of motor vehicles to make their vehicles theft-proof seem to contradict the conventional judicial wisdom that the theft and bad driving by the thief are not broadly within the risk of leaving a motor vehicle unlocked.

Some English courts have tried to steer a different course in respect of intentional intervening acts of third parties. They have suggested that a defendant should be liable only where the intentional intervening act is very likely to happen. Canadian courts, however, seem content to resolve the issue under the concept of reasonable foreseeability, albeit a foreseeability that continues to be interpreted in a manner that is quite protective of defendants.

c) Suicide

The suicide of an accident victim presents difficult challenges for negligence law. It arises most commonly where a person, who is permanently disabled by the negligence of a defendant, is unable to adjust to and accept his post-accident situation, becomes clinically depressed, and subsequently commits suicide. There are policy reasons both for and against imposing liability on the defendant for the death. The imposition of responsibility can be supported on the grounds that the defendant's death would not have occurred but for the defendant's negligence and that a finding of liability furthers the compensatory and deterrent goals of negligence law. The denial of liability can be supported on the grounds that the direct cause of the death is the deliberate act of the deceased, that the defendant had no control over or responsibility for the conduct of the deceased, that suicide is a rare consequence of traumatic injury, and that there is a general societal discomfort with, and disapproval of, suicide. A judicial reluctance to hold a defendant, whose negligent act may have been relatively minor, publicly accountable for the death of a person should also not be discounted.

Legal principles can accommodate either view with relative ease and the cases are not consistent. Liability can be imposed on the basis of the thin-skull rule. [Note 144: Gray v. Cotic, [1983] 2 S.C.R. 2.] It can be avoided on the ground that the deceased's act was an unforeseeable intervening act. [Note 145: Wright Estate v. Davidson (1992), 88 D.L.R. (4th) 698 (B.C.C.A.).] There is also support for the view that liability should be imposed only if the defendant's negligent act directly impaired the deceased's rationality and that impairment led to his suicide. [Note 146: Swami v. Lo (No. 3) (1980), 105 D.L.R. (3d) 451 (B.C.S.C).] This might arise where the defendant's negligence caused brain damage that impaired the deceased's sanity and ultimately led him to take his own life. This line between "sane" and "insane" suicide is, however, a difficult one to draw.

Overall, the weight of authority is against liability for the suicide of an accident victim. The few decisions going the other way may reflect sympathy for the family of the deceased and its compensatory needs and may anticipate a more generous approach in the future.

CHAPTER 2, NEGLIGENCE: BASIC PRINCIPLES