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Proximate Cause

See Also:


Proximate Cause: 
Cause that is legally sufficient to result in liability.

An expected outcome of the defendant's acts. 

Eggshell Plaintiff:
A plaintiff who, either because of a physical ailment or extreme sensitivity, suffers harm that most people would not have suffered.

Contributing Factors:
Factors which are already in operation when the defendant acts (a physical disability).

Actual cause, the topic of the last chapter, is a legal determination used to establish a defendant's liability. Proximate cause, on the other hand, is a policy determination used to limit a defendant's liability. That being the case, we do not consider proximate cause unless we have established actual cause.

Essentially, the concept of proximate cause is what the courts will use to determine how far the defendant’s liability extends for unforeseen consequences. For example:

Mrs. O’Leary negligently starts a fire in her house and the fire spreads to twenty other houses on the block. The issue of proximate cause will be used to determine whether Mrs. O’Leary will be liable for all twenty houses. Under the circumstances, it might not be fair to hold Mrs. O’Leary liable for all twenty houses, especially if the burning of the other houses was unforeseeable. Thus, while Mrs. O’Leary’s actions would be the actual cause of all twenty houses burning, the court may deem that it was not the proximate cause of all twenty houses burning and therefore would not hold her liable for all twenty houses.

Whether the defendant’s actions are the proximate cause of plaintiff’s injury depends on the forseeability of the harm caused. See Parness v. City of Tempe, 600 P.2d 764 (Ariz. 1979).

Under the forseeability approach, proximate cause questions will fall into one of three basic categories:

The first category involves situations where a foreseeable result occurs in an unforeseeable or extraordinary manner. The general rule is that, where the results are foreseeable, liability usually attaches because, if the defendant causes a foreseeable injury, this usually presents a clear enough case of liability that proximate cause is rarely in doubt. However, there are certain foreseeable results for which liability does not attach. Some courts will not impose liability on the defendant where the harm, although foreseeable, has come about in a highly extraordinary manner. Here are two examples:

  1. Ishmael, a crew member on a whaling ship, fails to properly seal the fuel tanks on the ship. The result is that the ship’s hull fills with gasoline fumes. Later that day, the ship is struck by lightning. The fumes are ignited and the boat explodes. Here, Ishmael may not be liable for the explosion. Although the explosion was a foreseeable result of Ishmael’s negligence, and although Ishmael’s negligence was the actual cause of the explosion, the explosion has come about in such a highly extraordinary manner that Ishmael’s negligence will not be considered the proximate cause of the explosion.
  2. Ishmael negligently takes his eyes off the road while driving though an intersection. Ahab is crossing the intersection at the time. When Ishmael sees Ahab, he swerves his car to try and avoid hitting Ahab. In swerving his car, he crashes into a brick wall. The brick wall begins to crumble. The crumbling wall knocks over a tree standing next to it. The tree falls, lands on Ahab and breaks his arm. Although the harm here is foreseeable (it is foreseeable that if you take your eyes off the road you might hit a pedestrian and cause him broken bones),

    Ishmael’s negligence, although the actual cause of the accident, will not be considered the proximate cause of Ahab’s injuries.

The second category of proximate cause questions, involves situations where the foreseeable plaintiff has been injured but an unexpected extent or type of harm has occurred. Where the injury suffered was unforeseeable and occurred without the influence of any intervening force, there is a split in the courts as to whether or not the defendant should be liable. Some courts hold that the defendant is liable for all direct consequences of his negligence even if the consequences are unforeseeable. However, most courts reject this approach and hold that when an unforeseeable result occurs, the defendant will not be held liable. See Benn v. Thomas, 512 N.W.2d 537 (Iowa 1994).

Here are two examples:

  1. While unloading Ahab’s ship, Ishmael negligently throws a wooden plank into the hold. Gas fumes were present in the hold of the ship and when the plank hit the bottom it created a spark that ignited a fire which in turn destroyed the ship. According to some courts, the defendant is liable for all direct consequences of his negligence, even if the damage is unforeseeable. Those courts would hold Ishmael liable for the destruction of the ship even though the fire was an unforeseeable event and the destruction of the ship was an unforeseeable harm. However, according to most courts, which hold that when an unforeseeable result occurs, it is unfair to hold the defendant liable, Ishmael would not be held liable for the destruction of the ship.
  2. Ishmael and Ahab are on a horse farm. Ishmael finds a beebee gun and begins shooting in Ahab’s general direction. One of the beebees misses Ahab but hits Ahab’s car, setting off the alarm. The alarm startles one of the horses who breaks into a run and tramples Ahab. In this case, Ahab is the foreseeable plaintiff. However, the harm that Ahab suffered is certainly unexpected. One might expect Ahab to suffer an injury as a result of being hit with a pellet or as a result of trying to run away from Ishmael. However, getting trampled by a horse is unforeseeable and so, in most jurisdictions, Ishmael would not be held liable for Ahab’s injuries.

The most common examples of unforeseeable extent of injuries involve cases with what is called an “eggshell plaintiff”. An “eggshell plaintiff” is someone who has some sort of physical or mental ailment that has been exacerbated unexpectedly by the defendant’s negligence. Alternatively, he is a plaintiff who simply has a very low tolerance for whatever negligent action the defendant undertook. In such instances, all courts will hold the defendant liable for the full extent of plaintiff’s injuries. For example:

Unbeknownst to Ishmael, Ahab is unusually sensitive to sudden loud noises. Ahab also has a variety of heart problems. Ishmael negligently sets off a firecracker while Ahab is sleeping. The noise scares Ahab so badly that he suffers a heart attack. Although some sort of nervous reaction might be a foreseeable result of Ishmael’s action, Ahab suffering a heart attack is probably not foreseeable. However, that being said, a defendant must take his victim as he finds him and thus, even though Ahab’s heart attack was an unforeseeable extent of the injury he suffered, Ishmael is still liable.

As the above example indicates, preexisting conditions are not considered intervening acts. (We'll get to intervening acts in the next chapter). Preexisting conditions are contributing factors that are already in operation when the defendant acts. Although, in the previous example, Ahab’s physical condition combined with Ishmael’s negligence to cause an unexpected injury, Ahab’s physical condition, the heart problem, is not an intervening act. It is considered part of the “set stage" that a plaintiff operates on.

The third category of proximate cause questions, involves situations where the defendant’s act exposed a certain group of potential victims to a foreseeable risk but the person harmed was not a member of that group. Our previous discussion of the Palsgraf case provides a perfect example. As you recall, Justice Cardozo determined that the exploding package put a certain group of potential victims, those within the zone of danger, at foreseeable risk. Mrs. Palsgraf, standing thirty feet away, was not a member of that group. Because she was not a member of the foreseeable victim group the exploding package was not considered the proximate cause of her injuries even though it was the actual cause of her injuries. Judge Andrews, on the other hand, finds liability if the harm can be causally linked to the negligent action. In this regard, Judge Andrews avoids the problem of proximate cause altogether.