The dictates of Jerista apply to the facts presented here. The res ipsa inference of negligence is applicable because common experience instructs that elevator doors -- however complex their operation may be -- ordinarily should not strike a person entering or exiting an elevator in the absence of negligence. To warrant the inference, plaintiff had no obligation to exclude other possible causes that might explain the malfunctioning of the elevator doors or to show that defendants were on notice of some defect in the doors’ operation.