Two men are hospitalized in critical condition after a flash fire at a house where they were working in Council Bluffs. Fire Department spokesman Rick Benson says the two were refurbishing a wooden floor in an old home.

Two workers for an Omaha floor-refinishing company were using some flammable chemicals to resurface a floor in a vacant house. Somehow the flammable fumes built up in the house from the chemicals they were using were ignited by a spark, an in the flash fire that resulted, the two were badly burned.

The building itself didn’t suffer serious damage from the flash fire, which may have been caused by an electric floor buffing machine according to some reports. Benson says the fire in the house sounds like a typical flash fire — once the chemical vapors ignited, they quickly burned out, though they injured the workers and ignited their clothes. The two men were taken to Creighton Hospital in Omaha.