The tragic bus accident that occurred early Saturday morning in the Bronx claimed its 15th victim Monday morning, amid reports that the driver of the bus could have been sleepy on the job. Investigators said that bus driver Ophadell Williams arrived at the Mohegan Sun Casino in Connecticut around 11 p.m. Friday evening to drop off passengers, slept in the casino parking lot, and then was back up at 3 a.m. Saturday to pick up a new group bound for New York. The bus crashed on I-95 in the Bronx at about 5:30 a.m., with the entire top of the bus sheared off by a highway sign post. NBC New York also reported that some passengers claimed the bus was drifting in and out of lanes and hitting rumble strips on the side of the highway prior to the crash, and that the driver's claim that the bus was clipped by a tractor-trailer was inaccurate. The bus, operated by World Wide Travel, was carrying 31 passengers and skidded for 480 feet before it crashed, leading state police to believe it may have been speeding past the 55 mph limit. Williams did pass a Breathalyzer test at the scene, according to reports. The names of the 15 victims have yet to be released.