Andrews

Opinion by Judge KOZINSKI.

We are called upon to determine whether United Airlines took adequate measures to deal with that elementary notion of physics— what goes up, must come down. For, while the skies are friendly enough, the ground can be a mighty dangerous place when heavy objects tumble from overhead compartments.

I

During the mad scramble that usually follows hard upon an airplane’s arrival at the gate, a briefcase fell from an overhead compartment and seriously injured plaintiff Billie Jean Andrews. No one knows who opened the compartment or what caused the briefcase to fall, and Andrews doesn’t claim that airline personnel were involved in stowing the object or opening the bin. Her claim, rather, is that the injury was foreseeable and the airline didn’t prevent it.

The district court dismissed the suit on summary judgment, and we review de novo. Dorsey v. National Enquirer, Inc., 973 F.2d 1431, 1434 (9th Cir.1992). This is a diversity action brought in California, whose tort law applies. Id.

II

The parties agree that United Airlines is a common carrier and as such “owe[s] both a duty of utmost care and the vigilance of a very cautious person towards [its]…