Officials will examine footage from a video camera mounted inside the tour bus that crashed and killed 15 people on a New York highway after the driver's account has been questioned.
The National Transportation Safety Board said it will analyze footage from the camera that faced passengers and will also examine an engine control module that may indicate how fast the bus was going when it crashed early Saturday. The bus slid into a sign pole that sheared the vehicle end to end in a gruesome scene of blood, jumbled bodies and shattered glass.
Passengers and witnesses to the horrific crash that sheared the top off the bus told investigators that the driver's account of getting clipped by a tractor-trailer didn't match up to what they felt and saw before the vehicle slid off the road and into a sign pole.
Driver Ophadell Williams had told police that his bus was hit just as it crossed the New York City line early Saturday on a trip from the Mohegan Sun casino in Connecticut.
But passengers said Williams had already swerved at times to the right for no reason before the accident, a law enforcement official said Sunday. The official wasn't authorized to speak publicly about the probe and spoke on condition of anonymity.
The bus was returning to Manhattan's Chinatown after a quick overnight trip to the casino. The official said that passengers said they didn't feel anything hit them and that other motorists on Interstate 95 said they didn't see the bus get hit. The official said police spoke to the tractor-trailer driver, who said he was following the bus.
Williams was hospitalized in stable condition after the crash and was released Sunday night, St. Barnabas Hospital spokesman Howard Matzner said. Williams hasn't commented publicly.
As many as 20 passengers were treated at hospitals following the accident. Several remained hospitalized early Monday. Most were in critical condition.
New York City medical examiner's office said over the weekend that 14 people -- eight men and six women -- died from blunt force trauma. On Monday, authorities said a 15th victim -- a 70-year-old man -- had died from his injuries.
His name and the names of 14 others haven't been released.
The National Transportation Safety Board has interviewed two passengers from the bus, but it hasn't spoken to the bus driver or the driver of the truck, Vice Chairman Christopher Hart said at a news conference late Sunday.
He said the investigation was still in its early stages, but the NTSB plans to talk to the bus company to see what kind of fatigue management the company has in place. Investigators will also look into the casino's records to see whether the driver checked into a room there.
Some of the 31 passengers were still asleep when the bus crashed at 5:35 a.m. Saturday. The bus scraped along the guard rail for 300 feet, toppled and crashed into the support pole for a highway sign indicating the exit for the Hutchinson Parkway. The pole knifed through the bus front to back along the window line, peeling the roof off all the way to the back tires.
The bus was one of scores that travel daily between Chinatown and the Foxwoods and Mohegan Sun casinos in southeastern Connecticut.
Mohegan Sun, in Uncasville, Conn., has estimated a fifth of its business comes from Asian spending and caters to Chinese-American gamblers. Its website has a Chinese-language section offering gaming and bus promotions.
The trips between New York City's Chinatown and regional casinos are popular, said Eddie Chiu, who runs the Lin Sing Association, a community outreach group.
He said in the past three years, there have been a handful of serious accidents involving discount buses taking people from New York's Chinese community to casinos.
"The drivers tell me that they're often very tired," he said, adding that salaries are low and drivers work long hours.
Eric Brodie, a spokesman for the bus operator, World Wide Travel, said company officials met with NTSB and state police investigators and were cooperating fully. He declined to comment further.
The accident tossed passengers all around the bus, with most people hurled to the front of the bus on impact, authorities said.
Many of the passengers on the bus were Chinatown residents. They ranged in age from 20 to 50, officials said.
Chinatown community organizations offered to help victims' families cope with their loss.
Oanfa Quan, who runs a company that provides wigs and medical prostheses, said she was working with the Lin Sing Association to provide wigs in case some of the victims need them for burial.
"Usually the family wants it for their own peace of mind," she said. "Even if the casket is closed, they still want to know that their loved one looks the way they were prior to the accident."
The Associated Press contributed to this report