OGDENSBURG - A veteran state trooper and a Canadian man were electrocuted while fixing a flat tire on an antique fire truck when the truck's ladder touched a high-voltage power line.

Trooper Shawn Snow, 47, and Pierre Surprenant, 51, of Lachenaie, Quebec, were killed instantly Sunday in the freak accident, Ogdensburg police said. “This type of accident is somewhat incomprehensible,” said Maj. Richard C. Smith Jr., commander of state police Troop B in Ray Brook. “It is a terrible day.”

Snow was a 19-year veteran and was assigned to the commercial vehicle enforcement unit. He was responsible for inspecting trucks that crossed the Ogdensburg-Prescott International Bridge or traveled area roadways, Smith said.

The incident occurred about 4:45 p.m. Sunday when police received a call about a fire truck on fire with people underneath it near the Ogdensburg-Prescott International Bridge.

The fire truck heading to Canada was towing a trailer with an antique fire chief's car when the truck had a flat tire on the road approaching the bridge, said Police Chief Richard Polniak. Snow stopped to help replace the flat tire.

The trooper was under the truck fixing the tire while the Canadian man was extending the truck's ladder to redistribute the weight away from the flat right rear tire. When the ladder hit a live wire, both men were killed, police said.

“How it ended up touching the wires, whether a piece of equipment failed and it slipped and touched the wires, or whether the act of jacking it up higher on one side caused it to touch, we just don't know yet,” Polniak said.

The international bridge was closed for nearly nine hours, with traffic diverted to the Thousand Islands and Seaway bridges.

The fire truck was from the Canadian Fallen Firefighters Foundation and was on its way back to Canada from a parade near Syracuse.

A state police accident reconstruction team was investigating the incident.