MOUNTAIN HOME, Idaho - Police say three firefighters prepping a fireworks show in southwestern Idaho were hospitalized Sunday after the display was prematurely ignited.

Mountain Home Police Sergeant Rick Viola says investigators are working to determine the cause of the fire that set off the annual Fourth of July fireworks show hours before it was scheduled to start.

The blaze seriously injured one firefighter and hurt two others, destroying about $30,000 worth of pyrotechnics. All three firefighters were taken to Elmore Medical Center for treatment and two were later released.

A Mountain Home Police Department dispatcher told The Associated Press on Monday that the third firefighter has also been released from the hospital, though he is expected to receive additional treatment at a Salt Lake City burn center.

Mountain Home Mayor Tom Rist says the fireworks were not rigged to ignite when they exploded and firefighters believe that static electricity may have been the culprit.

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