The North Carolina Highway Patrol says just before 10 p.m. EDT on I-95 North near mile marker 135 in Rocky Mount a tractor trailer transporting six Thoroughbred racehorses from Florida to New York caught fire killing all the horses.

One of the horses reportedly was a recent sales purchase owned by Dream Team Racing, co-owners of Kentucky Derby contender Mucho Macho Man.

A Highway Patrol troop told WITN.com news outlet in Eastern North Carolina that the driver of the tractor trailer said she smelled smoke and pulled over and realized the hay inside was on fire. She tried to extinguish the fire but was unsuccessful. A back-up driver in the truck also tried to put the fire out but it quickly got out of control. One of the drivers suffered burns while trying to save the horses.

Three fire departments responded. Once on the scene, they realized the fire was started by a cigarette they say that a passer-by most likely flicked out of their car, according to the Nash County Sheriff’s Office. West Mount Fire Department was in charge of the scene