Legal Definitions - alternative liability

Alternative liability is a legal doctrine that applies in specific situations where multiple parties have acted negligently, and only one of them actually caused an injury, but it is impossible for the injured party to prove which specific defendant was responsible.

In such cases, the burden of proof shifts from the injured party (the plaintiff) to the negligent parties (the defendants). Each defendant must then prove that they did not cause the injury. If they cannot, they may all be held responsible for the harm.

This doctrine is an exception to the general rule that a plaintiff must prove which defendant caused their injury. It prevents wrongdoers from escaping liability simply because the specific cause of harm cannot be identified among a group of negligent actors.

• Example 1: Pesticide Contamination

  Imagine a farmer whose entire crop is ruined by a specific type of pesticide contamination. The farmer had purchased identical batches of this pesticide from two different chemical suppliers, Company A and Company B, both of whom had negligently produced contaminated batches. Forensic analysis confirms the presence of the contaminant but cannot definitively determine whether it originated from Company A's batch or Company B's batch, as both were used on the fields.

  How this illustrates alternative liability: Both Company A and Company B acted negligently by supplying contaminated pesticide. The farmer's crop was ruined by only one source of contamination (or it's impossible to distinguish between the two). Because the farmer cannot prove which specific company's pesticide caused the damage, the burden of proof shifts to Company A and Company B. Each company must now prove that their pesticide was *not* the source of the contamination that ruined the crop. If neither can, both may be held liable.

• Example 2: Construction Site Accident

  A pedestrian is walking past a large construction site where two different subcontractors, "Steel Erectors Inc." and "Facade Installers LLC," are working on adjacent sections of a building. Both companies have negligently left tools and materials unsecured on upper levels. The pedestrian is suddenly struck and injured by a falling wrench. Due to the chaotic nature of the incident and the similar types of tools used by both companies, it is impossible to determine whether the wrench belonged to Steel Erectors Inc. or Facade Installers LLC.

  How this illustrates alternative liability: Both Steel Erectors Inc. and Facade Installers LLC were negligent in securing their tools. Only one wrench caused the injury. The pedestrian cannot identify which specific company's negligence led to their injury. Under alternative liability, the burden shifts to Steel Erectors Inc. and Facade Installers LLC. Each company must prove that the wrench that fell was not theirs, or that their negligence did not cause the injury. If they cannot, both could be held responsible.