The driver of the tour bus that crashed early Saturday morning, killing 15 people, told police that he took a nap on the bus in a casino parking lot in the hours before picking up passengers for the southbound trip along I-95 to Chinatown, investigators said.
The bus crashed in the Bronx on its way back to New York from Mohegan Sun casino, skidding into a highway sign post, which entered through the front window, shearing the bus from front to back along the window line, cutting like a knife through the seating area.
The bus driver Ophadell Williams blew a .00 in a blood-alcohol test at the scene and voluntarily offered blood for a more precise blood alcohol test, officials said.
It also appears that Williams did not have his driver's log kept up to date as required, the officials briefed on the case said. Police wanted to check that log to see how much time he was spending on the road and what kind of breaks he was receiving between trips.
The driver arrived at the Mohegan Sun Casino around 11 p.m. to drop off passengers, said sources who are working to piece together a timeline of the horrific crash. According to those sources who recounted the driver's story, Williams then drove to a lot and took a nap until he was called back to pick up a group for a trip to New York at 3 a.m.
Investigators said he arrived at the front door of the casino around 3:15 a.m and departed at 3:45 a.m.
As NBC New York first reported, some passengers said the bus seemed to be drifting in and out of lanes and hitting rumble strips on the side of the highway. Some told police they feared the driver was tired or distracted.
Police said they also found the driver of the tractor trailer who the bus driver allegedly claimed had cut him off. That truck driver said the tour bus was ahead of him drifting in and out of lanes, officials briefed on the case said.
A preliminary inspection of the truck revealed no evidence of any collision or contact between the bus or the truck, said the same officials who stressed that the investigation into the crash is still in its early stages.
The National Transportation Safety Board said at a briefing on Sunday that the bus, which was carrying 31 passengers from the casino to Manhattan's Chinatown, slid for 480 feet before it came to a stop.
In addition to the fatalities, six other passengers were critically hurt. Ten out of the injured people have been treated and released.St. Barnabas Hospital said it had discharged Williams on Sunday night..
Authorities, including Mayor Bloomberg, made pleas on Sunday for anyone who might know someone on the bus to call 311. One of the survivors who is hospitalized has yet to be identified.
The medical examiner said on Sunday that some identifications of the dead have been delayed and will depend on fingerprint analysis and X-rays because of the extensive trauma they suffered.
The agency did say that of the dead, eight are men and six are women. The formal cause of death is blunt force trauma. First responders said it was among the worst crash scenes they had ever seen -- a tangle of limbs and carnage amid the twisted metal.
Several passengers who survived Saturday's crash told police the bus driver was speeding and driving erratically down I-95 before the accident, two law enforcement sources told NBC New York.
One official familiar with the case said investigators are looking into whether the driver fell asleep behind the wheel of the bus -- or was somehow not paying attention just before the 5:30 a.m. crash in the Bronx.
The officials stressed operator error was just one theory based on passenger statements.
Investigators are now reviewing what the driver was doing the night before the crash. The NTSB said Sunday that its investigators will be examining tapes from the casino to see what the driver was doing up to 72 hours prior to the accident.
State police said the bus might have been speeding faster than the 55 mph limit.
The driver's wife, Holly, told the New York Daily News that Williams "feels like he's at fault."
"But I told him it's not his fault -- it's an accident. He feels upset that a lot of people died on his bus."
Investigators said they will review a video camera from inside the bus and other evidence in the wreckage to try to determine the speed of the bus when it crashed.
"It will take a considerable amount of time to determine what, if any, criminal act may have occurred here," State Police Major Michael Kopy said.
According to the Federal Motor Carrier Safety Association's website, drivers from the tour bus company have previously been cited for "fatigue driving."
In an earlier statement, World Wide Travel, the tour bus company, said the company will cooperate with the investigation. The company did not return calls or emails requesting comment on these latest developments.