South Hadley Fire Chief Robert Authier said three of his firefighters are lucky following an explosion in a mobile firefighter training unit.
"It was a close call for everybody," Authier told MassLive.com. "It could have been body bags."
Firefighters were using the state's Mobile Live Fire Training Unit at their station Tuesday when the explosion occurred.
Officials speculate that a build up of propane in the Massachusetts Fire Academy unit is to blame for the blast.
"Right now, it looks like an uncontrolled ignition of gas," state Fire Marshal Marshal Peter J. Ostroskey told MassLive.com.
South Hadley crews were on their third or fourth evolution when the blast occurred.
One firefighter suffered a concussion and the other sustained burns to his face and both were taken to the hospital. They were later released.
A third firefighter suffered minor injuries and was treated at the station.
The mobile training unit was taken out of service while investigators determine the cause of the explosion.
