Missouri firefighters say six people have been injured in a propane explosion at a trucking company, leaving one of them with critical burns..
The explosion happened about 8 p.m. Thursday at SAIA Motor Freight Line.
Fire Department Capt. Garon Mosby says workers were trying to switch out a propane tank on a forklift when a leak from the tank caught fire and caused a flash explosion.
The tank didn't explode and nothing caught fire.
The cause of the leak has not been determined. Authorities haven't released the victims' names.
In addition to the man with critical injuries, three other workers are hospitalized with serious burns and are listed in stable condition. Two workers refused treatment for what were described as minor injuries.
The investigation is ongoing.