On two separate occasions, McGlynn and Backer (plaintiffs) parked their cars in an underground parking garage operated by the Parking Authority (Authority) (defendant). Drivers entering the garage parked in any available space, locked their cars, and retained their keys. Upon exiting, the drivers stopped at a booth to pay the parking fee. On the day McGlynn parked in the garage, he returned to find that vandals had slashed his convertible top and stolen a cassette recorder and 40 cassettes. On the day that Backer parked in the garage, he returned to find that thieves had stolen four hubcaps and broken the car’s antenna. McGlynn and Backer brought complaints against the Authority, claiming that the Authority was liable for the damage to their cars due to breach of a bailment contract. An Authority supervisor testified that the garage was regularly patrolled by attendants and police, but conceded that prior incidents of theft and vandalism had occurred. The trial judge concluded that a bailment relationship existed in both cases. The judge instructed the jury that a presumption of negligence arose upon proof of damage. The jury found in favor of both McGlynn and Backer, awarding damages. The Authority appealed.