Updated

A chain-reaction crash that started when a tractor-trailer rear-ended a vehicle in a work zone in northern New York on Thursday left six people dead, state police said.

Trooper Jack Keller said all five people killed were riding in an SUV that had stopped or was moving slowly Thursday morning because of road repaving on Route 11 in the Jefferson County town of Antwerp. He said the truck slammed into the back of one vehicle, causing collisions with a state Department of Transportation truck and the SUV, which burst into flames.

A woman and a transportation worker were in critical condition, Keller said. The tractor-trailer driver was taken to a hospital for treatment and will be tested for drugs and alcohol, he said.

The SUV that carried five people was registered in New York, Keller said. Police were attempting to determine if all five victims were from the same family, he said.

Keller said the driver of the first vehicle died at a hospital.

The crash happened near Fort Drum, 85 miles northeast of Syracuse. The collision occurred along a straight, flat section of two-lane Route 11, the main east-west road across four rural northern counties along the Canadian border. There were plenty of signs warning motorists approaching the area that crews were working on the road, Keller said.

"(The tractor-trailer) plowed right into them," he said by telephone from the scene. "We're trying to determine what happened."

DOT spokesman William Reynolds confirmed that a state crew was repaving the road and that one of the agency's employees was injured and airlifted to a hospital in Syracuse. The federal National Transportation Safety Board had been notified and investigators are en route to the crash scene, Reynolds said.

Route 11 will remain closed for several hours.