Updated

Seven people, including four children under 10, were killed when a tractor-trailer collided with a minivan on a rural two-lane highway in upstate New York on Wednesday, according to authorities.

The rig was headed south around 6 p.m. on Route 13 about 25 miles south of Syracuse when its trailer became disconnected and crossed the center line, hitting a minivan carrying eight people, according to Capt. Mark Helms of the Cortland County Sheriff's Department.

The force of the impact ripped the minivan apart, and both vehicles came to rest on the shoulder of the roadway.

"It was a bad accident," Helms said.

Officials have not released the identities of those killed, but all of them were passengers in the minivan. Cortland County Coroner Whitney Meeker said Thursday that all the victims, including four children under 10, were local residents.

Meeker added the children were from two different families, including one from Truxton. She said there was one survivor who was taken to Upstate University Hospital in Syracuse. The status of that survivor was not immediately known

Meeker said it will probably take the next two days to complete autopsies. She said next of kin would be notified early Thursday at the Cortland County Sheriff's office.

Two people who were riding in the truck were not injured in the crash, Helms said.

Officials did not say what caused the accident.

The National Weather Service in Binghamton said there were thunderstorms and steady showers -- including hail -- in the area around Truxton Wednesday evening.

Douglas Randall, the fire commissioner for nearby Town of Cuyler, said he was directing traffic about a mile north of the crash site when he saw what he believed to be hysterical family members being escorted away from the scene.

"They were all meeting down the road at a family member's house," he said. "They were all hysterical."

The Associated Press contributed to this report.