Seven people, including four children, are dead after a tractor-trailer collided with a minivan on a rural two-lane highway in upstate New York, officials said Wednesday.

The Associated Press said the accident happened around 6 p.m. when the rig was headed south on Route 13, about 25 miles south of Syracuse, and became disconnected before crossing the center line, hitting a minivan carrying eight people.

Capt. Mark Helms of the Cortland County Sheriff's Department told reporters that 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.

Cortland County Coroner Whitney Meeker confirmed to AP that seven people died in the crash. She said there was one survivor who was taken to Upstate University Hospital in Syracuse. The condition of the survivor wasn't immediately known.

Identities of those killed haven't yet been released, but it has been said that all of them were passengers in the minivan. Two people in the tractor-trailer weren't injured, Helms said.

While officials didn't 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 on Wednesday evening.