First Principles of Business Law

6. Causation

6.2.5. Multiple independent causes of harm

Case study: A drives his car into B's car wash. Because he does not slow down to a safe speed, he collides with the console that houses the washing equipment, causing such extensive damage that the equipment will need to be replaced at a cost of $5,000. Before the replacement is done, C coincidentally also drives too quickly into B's car wash and collides heavily with the same console. Consider both of the arguments below. Which of them do you think is correct?

(a) In cases such as this, the damage caused by the first collision is complete and is not altered or increased in any way by the second. It follows that if the second collision did not cause any additional harm, C is not liable in tort to B for any of the cost of the replacement console.

(b) In cases such as this, because it is apparent that the later negligent conduct was sufficient on its own to cause the harm in question, the responsibility for the harm suffered should be apportioned between both the negligent parties, since it is unfair to hold the first defendant alone liable.