Generally, in tort, the mere fact of an accident is not proof of negligence. But in some cases, negligence is presumed on the defendant since the object causing injury was in or under his or her control. This is the res ipsa loquitur doctrine.
Res ipsa loquitur is a rebuttable presumption rebutted by showing that the event was an inevitable accident and had nothing to do with the defendant’s responsibility of control or supervision.
Examples of res ipsa loquitur, not all of which can be assumed to apply today or in all jurisdictions, but which illustrate the doctrine:
Getting hit by a rock which flies off a passing dump truck;
A ship in motion collides with an anchored ship;
Damages occasioned by the collision of two trains of a same railway;
Hit or injured in an attack by a known-to-be vicious domestic dog;
Hit from cargo falling from a crane; or
Hit by bricks falling from a private bridge.
These events imputes negligence (res ipsa loquitur) and can only be defeated if the defendant can show that the event was a total and inevitable accident.