What is a required condition for res ipsa loquitur to apply in a negligence case?

For res ipsa loquitur to apply in a negligence case, it is essential that the event causing the injury must be under the defendant's control. This principle allows a plaintiff to establish negligence when direct evidence is unavailable, relying instead on the circumstances surrounding the incident. By demonstrating that the harm occurred in a situation that typically wouldn’t happen without negligence, the plaintiff can invoke the doctrine effectively.

The requirement that the event must be under the defendant's control underscores the idea that the defendant had the ability to prevent the harm from occurring. If the event resulting in injury could have been controlled or managed by the defendant, it strengthens the assumption of negligence since they had the responsibility to ensure their actions or property did not cause harm to others.

In scenarios where harm occurs outside the defendant's control, it becomes more challenging to apply res ipsa loquitur because it lacks the connection that points to their negligence. Thus, the focus on control is a crucial aspect in establishing a presumption of fault in negligence cases.