NEW YORK – Fourteen people died and others were maimed Saturday when a bus returning to New York City from a casino overturned on a highway and was sliced, end to end, by the support pole for a large sign.

The driver, who survived, told police he lost control while trying to evade a swerving tractor trailer. Police began a hunt for the truck, which did not stop after the crash, New York Police Commissioner Raymond Kelly said.

The early-morning wreck left a scene of carnage and closed the southbound side of Interstate 95 for hours while emergency workers tended to critically injured survivors and removed bodies.

The bus, operated by World Wide Tours, was headed to Manhattan’s Chinatown neighborhood loaded with passengers returning from the Mohegan Sun casino in Uncasville, Conn.

According to the driver, the accident was triggered by a close encounter with a tractor trailer as the two vehicles were entering city limits from Westchester County at 5:35 a.m. The bus was in one lane. The truck was in the lane to its left.

“The truck either starts to swerve or perhaps even hits the bus,” Kelly said. As the bus took evasive action, it hit a guardrail, scraped along it for 300 feet, toppled and crashed into the support post for a highway sign indicating the exit for the Hutchinson Parkway.

The pole entered through the front window, then sheared the bus from front to back along the window line, cutting like a knife through the seating area and peeling the roof off all the way to the back tires.

Police and fire officials said the bus was carrying at least 31 passengers. Most were hurled to the front of the bus by the sudden impact with the pole, Fire Chief Edward Kilduff said.

Doctors were still working to save the lives of other, gravely injured passengers. One patient who had initially survived the wreck died at a hospital Saturday afternoon, said spokespeople for the police and the city’s medical examiner.

In addition to the fatalities, seven other passengers were critically hurt. As many as 20 were treated at local hospitals.

Survivors described a scene of horror.

Chung Ninh, 59, told The New York Times and NY1 News that he had been asleep in his seat, then suddenly found himself hanging upside down from his seat belt, surrounded by the dead and screaming. One man bled from a severed arm.

He said when he tried to help one bloodied woman, the driver told him to stop, because she was dead. “Forget this one. Help another one,” he said.

Limo driver Homer Martinez, 56, of Danbury, Conn., happened on the scene moments after the wreck and saw drivers sprinting from their cars to assist the injured. He said they were horrified by what they found.

“People were saying, ‘Oh my God. Oh my God,’ holding their hands on their heads,” Martinez said. “I saw people telling other people not to go there, ‘You don’t want to see this.’ “

Firefighters and medics were on the scene quickly.

“I see a lot of accidents. I’ve even seen accidents happen. But I’ve never seen anything like this,” Martinez said.

The southbound lanes of I-95 were still closed Saturday afternoon. Kelly said investigators had been given some numbers from the license plate of the tractor trailer, but hadn’t identified or located a vehicle yet.

The National Transportation Safety Board said it was sending a team of investigators.

Many of the passengers on the bus were residents of Manhattan’s Chinatown. The bus was one of scores that travel daily between Chinatown and the Foxwoods and Mohegan Sun casinos in Connecticut.

Mohegan Sun has estimated that 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.

Foxwoods is a major destination for Asian-American gamblers and has an Asian gaming room.