NEW YORK - A tour bus returning from a casino at daybreak Saturday scraped along a guard rail, tipped on its side and slammed into a pole that sheared it nearly end to end, leaving a jumble of bodies and twisted metal along Interstate 95. Fourteen passengers were killed.

The bus had just reached the outskirts of New York City on a journey from the Mohegan Sun casino in Connecticut when the crash happened. The driver told police he lost control trying to avoid a swerving tractor-trailer.

As many as 20 passengers were treated at area hospitals. Seven were in critical condition, according to police. Several were in surgery later in the day.

The crash happened at 5:35 a.m., with some of the 31 passengers still asleep. 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. Most people aboard were hurled to the front of the bus on impact, fire chief Edward Kilduff said.

The southbound lanes of the highway were closed for hours while emergency workers tended to survivors and removed bodies.

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.

Ninh 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 the driver told him. He said he and other passengers who were able climbed out through a skylight.

New York Police Commissioner Raymond Kelly said police were still looking for the truck, which did not stop after the crash.

He said the truck was in a lane to the bus' left, although it was unclear whether the two vehicles touched.

Kelly said both the bus and the rig were both moving at "a significant rate of speed."

Limo driver Homer Martinez happened on the scene moments after the wreck and saw other drivers sprinting from their cars to assist the injured.

"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.'"

Capt. Matthew Galvin of the NYPD's Emergency Service Unit was one of the first rescuers on the scene. He said when officers clambered into the wreckage, they found "bodies everywhere."

"People were moaning and screaming for help," he said. Some of the dead were tangled up with the living.

Though dazed, about seven people were able to walk away from the wreck on their own, he said. Galvin said that in his 22 years on the job, "It's probably the worst accident I've ever seen in terms of the human toll."

The southbound lanes of I-95 were still closed Saturday afternoon. The wreck also closed the northbound side of the highway, but those lanes were open again by midmorning.

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

After the crash, firefighters took out seats and cut through the bus roof to reach a handful of passengers pinned in the wreckage. Kilduff called it "a very difficult operation."

Many of the passengers on the bus were Chinatown residents. They ranged in age from 20 to 50, officials said.

Fifteen were being treated at Jacobi Medical Center in the Bronx. A hospital spokeswoman, Barbara DeIorio, said some injuries were serious but had no immediate information on how many were gravely hurt. Five more were taken to St. Barnabas Hospital, where two were on life support, breathing with the assistance of machines.

"We've had skull fractures, rib fractures ... internal bleeding, we've had lung contusions," said Dr. Ernest Patti, senior attending physician at St. Barnabas.

The bus driver was "awake and conscious," Patti said.

World Wide Travel, the operator of the bus, said it in a statement that the company was "heartbroken" and cooperating with investigators.

"We are a family-owned company and realize words cannot begin to express our sorrow to the families of those who lost their lives or were injured in this tragic accident. Our thoughts and prayers are with them," it said.

The bus was one of scores that travel daily between Chinatown, in Manhattan, and the Foxwoods and Mohegan Sun casinos in northeastern 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.