Thirty-three calves died after a tractor-trailer caught fire on the Thruway in Genesee County late Thursday night, State Police reported.

Jeffrey A. Foss, 53, of Vernon, was driving the westbound rig when he noticed flames coming from the right side of the trailer just before midnight, troopers said. He immediately pulled over and used his fire extinguisher, but the flames were too intense.

Firefighters from Bergen and Caledonia responded to the scene, in the Town of Leroy, and doused the blaze.

Of the 176 calves on board, 143 were saved, troopers said. Dr. Gerald R. Vukman, a livestock veterinarian from Oakfield, responded to the scene to help care for the animals.

No other injuries were reported. Troopers said the cause of the fire is believed to be a mechanical failure.