NEW YORK >> Passengers and witnesses to a horrific crash that sheared the top off a bus and killed 14 people 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 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.

Officials at Jacobi Medical Center were still trying to identify one passenger, an Asian man in his 50s, spokeswoman Barbara DeIorio said.

“He’s very injured. He’s not able to communicate yet,” she said, adding that the man was in the surgical intensive care unit.

The 14 victims — eight men and six women — all died of blunt force trauma, said Ellen Borakove, a spokeswoman for the New York City medical examiner’s office. She said the office was working with family members to identify them.

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.

The NTSB will analyze three devices: a camera mounted in the bus facing the passengers; an engine control module, which may tell how fast the bus was going; and a GPS tracking device from the tractor-trailer, said Hart.

Some of the 31 passengers were still asleep when the bus crashed at 5:35 a.m. Saturday. The bus scraped along the guardrail 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.”