Trailer comes unhitched from truck in NY, kills 7 including children

(CNN) -- A trailer came unhitched from a truck near Syracuse, New York, on Wednesday, and struck an approaching minivan, killing seven people, authorities said.

Four of the dead were children, likely under the age of 10, the Cortland County coroner's office told CNN.

One man survived and was brought to a hospital.

The minivan carrying eight passed through the town of Truxton on a rural highway Wednesday evening, said Capt. Mark Helms of the Cortland County Sheriff's Department

The tractor-trailer, with two people on board, was traveling in the opposite direction.

Authorities do not know what caused the trailer to come loose. But Sheriff's Lt. Robert Derksen told CNN affiliate YNN Syracuse that weather was not believed to be a factor.

No one on board the truck was hurt, authorities said.

The victims' official cause of death has not yet been determined. Autopsies are being conducted Thursday and Friday, coroner Whitney Meeker said.

CNN's Josh Levs contributed to this report.