Proximate cause, also known as legal cause, exists when the defendant’s negligent act is a substantial factor in bringing about an injury to the plaintiff. For example, in a wrongful death action, it is essential to prove that the wrongful act of the defendant was the proximate cause of death. Not only must it be shown that the injury was caused by the act of the defendant, but also that the specific injury caused the death.
A wrongful act is said to be a proximate cause of an injury where the injury would not have occurred without the act. It must produce the injury in a continuous sequence of events.
There can be more than one proximate cause of a plaintiff’s injuries and the existence of several proximate causes does not alone relieve any one defendant of liability. Therefore, if the actions of multiple defendants each are substantial factors in bringing about the plaintiff’s injury, it is said that all defendants proximately caused the injury.
Under certain circumstances, an event occurring between the time of a defendant’s wrongful act and the victim’s injury will relieve the defendant from liability. This depends on the nature of the event and the manner in which it affects the continuity of the wrongful act. Under Pennsylvania law, a defendant is not relieved from liability simply because another concurring cause is also responsible for producing the harm. The general rule is that “the mere happenstance” of an intervening negligent act will not relieve the original defendant of liability. For example, in one case, a negligent driver struck two firemen who were directing traffic away from a chemical spill on the road. The conduct of the driver was determined not to be a superseding cause which would relieve the chemical company of its liability to the firemen for negligently transporting the chemical.
To constitute an intervening cause which will relieve the original defendant of liability, it must break the continuity of causal connection between his wrongful conduct and the injury, and not be such that he should have reasonably anticipated and guarded against it.
A defendant is responsible for the consequences of his wrongful act despite the occurrence of an intervening cause of harm as long as the intervening cause is foreseeable. In determining whether an intervening act is the superseding cause under Pennsylvania law, the test is whether the intervening conduct was so extraordinary as not to have been reasonably foreseeable. The second defendant’s actions relieve the first defendant from liability only if a reasonable person would regard the occurrence of the second act as highly extraordinary or if the second act was extraordinarily negligent.
— Denise Ciampitti