One person was sent to the hospital after a draw furnace exploded at a business in Elk County Monday night.

It happened just before 11:30 p.m. at Advanced Heat Training in St. Marys.

The initial call came in as an explosion and fire, but as crews were on their way we’re told there was a second explosion.

“We found out they had a draw furnace that an individual was operating and for some reason the draw furnace exploded and it caused a secondary explosion,” Bill Kraus, the chief of the Crystal Fire Department, said. “That individual got hit apparently by the door from what we’ve been told.”

Firefighters told us there was heavy smoke and the flames were consuming the back of the building. Officials were eventually able to make their way to the fire.

“The owners actually arrived and told us where to get to [the fire] in the back,” Kraus said. “We made access to the back as we had a crew going to the front and we finally made our way to the fire to get it knocked down.”

Crews were able to get the fire under control in just a couple hours, but we’re told the inside of the building has a lot of damage.

“We won’t have a final damage estimate for a couple days, but there appears to be a lot of damage to the inside of the building,” Kraus said.

The State Fire Marshal is still investigating.