(FOX NEWS) -- Two volunteer firefighters were killed and three others were injured when their fire truck overturned while responding to a triple fatality highway accident in West Virginia on Saturday night, authorities said.

Five members of the Pratt Volunteer Fire Department were heading toward the wreck on the West Virginia Turnpike when their truck flipped and hit a rock wall, Kanawha County Commission President Kent Carper told the Charleston Gazette-Mail.

Two of the firefighters were confirmed killed while the three injured were taken to the Charleston Area Medical Center for treatment, according to officials.

“This is a tragic event and believed to be the worst accident our volunteer fire service has ever suffered," Carper said in a written statement.

The names of the victims and surviving firefighters were not immediately released. The extent of their injuries wasn’t made clear.

Local media reported three people were killed in the first accident the firefighters had been attempting to reach. The highway crash occurred Saturday evening after a vehicle heading the wrong way on Interstate 77 collided head-on with another.

According to WCHS FOX11, a male and female were killed in the car driving in the wrong direction. A second female was killed in the car they struck. The names of the three crash victims have not been released.

West Virginia Gov. Jim Justice was joined by U.S. Sen. Joe Manchin in tweeting condolences to the victims of the two accidents.

West Virginia State Police are investigating both crashes.

"Our thoughts and prayers are with all those involved in these accidents this evening and their families,” Carper said.

Copyright 2018 Fox News. All rights reserved.