Proximate Cause

Proximate cause is the legal concept that determines how far a defendant's liability extends for the consequences of their negligent conduct. Also called legal cause, proximate cause serves as a limiting principle that prevents defendants from being held responsible for every conceivable injury that might be traced back to their actions, no matter how remote or unforeseeable. The key question in proximate cause analysis is whether the type of harm that occurred was a reasonably foreseeable result of the defendant's breach of duty.

One of the most famous proximate cause cases in legal history is Palsgraf v. Long Island Railroad (1928), in which Justice Benjamin Cardozo articulated the foreseeability test for proximate cause. The court held that the railroad employees could not be held liable for injuries caused by an explosion that was triggered by a chain of events set in motion by their negligent assistance to a passenger — because the harm to the plaintiff was not foreseeable from the defendants' perspective. This case established that liability extends only to foreseeable plaintiffs and foreseeable risks.

An intervening cause is an event that occurs after the defendant's negligent act and also contributes to the plaintiff's injury. If the intervening cause was foreseeable, it generally does not break the chain of causation and the defendant remains liable. However, a superseding cause — an unforeseeable, independent event that significantly contributes to the plaintiff's injury — can cut off the defendant's liability by breaking the proximate causal connection between the original negligence and the ultimate harm.

In complex multi-vehicle accidents, toxic exposure cases, and cases involving criminal acts of third parties, proximate cause can be one of the most vigorously contested issues in personal injury litigation. For instance, a property owner who fails to provide adequate security may be held liable for a criminal assault on their premises only if it was foreseeable that criminal activity would occur given the circumstances. Expert testimony from accident reconstructionists, engineers, and security professionals can be critical in establishing proximate cause.