Denis Pilon, chief of Swift Current's fire department, said some sort of mechanical failure on the truck sparked the fire.
"The driver was able to tell us it was carrying fireworks," Pilon told CBC News Thursday. "That just made us start to stand back and just take a little bit longer before we attacked it and think the thing through and decide how we're actually going to do this."
Crews were dispatched around 10 p.m. CST to respond to a truck fire on the Trans-Canada Highway, also known as Highway 1, at an overpass at 11th Avenue NW. Pilon said the driver of the truck had to scramble out the passenger side to get to safety.
"The guy did everything right," Pilon said. "And you know, I can't blame him for stopping under the bridge. He had his life to worry about about. He had to get out of there."
Pilon added that since the driver was out and there was no risk to the public, a decision was made to let it burn.
It took about two hours for all fireworks to burn out.