Tort Law 101: The Importance of Causation

Lug Nuts

A tort is a civil wrong that can be redressed by awarding damages. The primary aim of tort law is to provide relief for the damages incurred and deter others from committing the same harms. One type of tort is a negligent tort, which is a failure to behave with the level of care that someone of ordinary prudence would have exercised under the same circumstances. To maintain an action in negligence, a plaintiff must establish that the defendant (1) owed a duty of care to the plaintiff, (2) that the defendant failed to perform the duty of care, (3) the failure was the proximate cause of the plaintiff’s damages, and (4) the plaintiff sustained an actual loss or injury.

A fundamental characteristic of tort liability law is that a party must have caused harm in a relevant sense to be held liable for it. A plaintiff cannot recover unless the negligence is the proximate cause of the injury. The plaintiff bears the burden of establishing causation.

Santos v. Zrams: A Battle of Causation

In March 2013, a jury awarded a plaintiff over $900,000 in damages when she suffered injuries when lug nuts were negligently installed in her vehicles when it was serviced at Aamco Transmission Center in Easton, PA. The plaintiff was driving about 55 miles per hour when she heard a noise coming from the vehicle. The vehicle began to swerve uncontrollably, almost causing an accident. The swerving caused the plaintiff’s body to whip inside the vehicle, resulting in back and shoulder injuries. The plaintiff’s complaint alleged cervical and shoulder strains and a herniated lumbar disc. The plaintiff was prescribed pain medication and underwent several injections and a laminectomy.

The defendant, Zrams, Inc. (owner of Aamco) contended that plaintiff’s injuries were completed unrelated to the near-crash incident. The defendant claimed that no car was struck nor did any wheels come of the car, so plaintiff’s injuries are not consistent with the incident. Furthermore, plaintiff failed to complain of any injuries at the scene and provide a false medical history to the medical professionals. Rather, at the time of the incident, the plaintiff was on family leave and receiving unemployment. Zrams contended that the plaintiff suffered unrelated injuries involving a gynecological condition that necessitated surgery, which caused her to be out of work. Allegedly the plaintiff had been treated previously for back injuries, too.


A defendant can escape liability if causation is not proven. To demonstrate causation, the claimant must establish that the loss they have suffered was caused by the defendant. In most cases a simple application of the “but for” test will resolve the question of causation. “But for” the defendant’s actions, would the claimant have suffered the loss? If yes, the defendant is not liable. If no, the defendant is liable. In this case, we would have to ask: But for the workers negligently installing the lug nuts on the plaintiff’s car, would she have been injured?

Pre-existing Health Issue

A defendant may also use a plaintiff’s pre-existing condition to rebut this element of causation. If the defendant can show that the injury is due to the some prior cause, or only exacerbated a previous injury, the defendant’s liability can be avoided or mitigated. However, a jury may be unconvinced with such evidence and believe the negligent act is causally connected to the injury suffered.

If you or a loved one has been injured in an accident, contact our experienced Pennsylvania personal injury attorneys. Our goal is to secure the best possible outcome in your case.  Contact our office for a confidential consultation to discuss your rights at 215-481-9979.

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