NEW YORK (AP) — A defense attorney says a casino bus driver had enough sleep before a New York City crash that killed 15 passengers.

Attorney Patrick Bruno made the comment Thursday while arriving for the start of Ophadell Williams' manslaughter trial.

Bruno says that on the day in question, Williams had "as much sleep as many other people routinely have."

The National Transportation Safety Board says the crash probably occurred because Williams had too little sleep and the bus company provided too little safety oversight.

Williams was driving from a Connecticut casino to New York's Chinatown when it crashed around 5:30 a.m. on March 12, 2011.

Authorities say the speeding bus ran off the highway, hit a guardrail, then toppled. A sign pole sheared off the roof.