The State Fire Marshal says gas vapors ignited by static electricity cause the explosion and fire Tuesday near a farmer’s co-op in Sioux Center. Flames erupted around two rail cars, as firefighters kept the blaze from spreading to other cars that contained either ethanol or gasoline.

Dave Schipper, a special agent with the State Fire Marshal’s office, says only one of 9 rail cars was leaking and he credits local firefighters with containing the blaze. The co-op and DNR are working together to clean up the mess. Schipper says he does not believe there are any "environmental issues" with the spill, since most of it was contained in a reservoir. The explosion happened as gasoline was being pumped from a rail car to a semi tanker.

The driver of the semi was last reported in critical condition and is being treated at a burn center in Lincoln, Nebraska. Schipper says the local firefighters should be praised for not letting the fire spread to other rail cars.

Schipper says, if the fire had spread, there could have been more explosions and train cars flying through the air. The fire, and the possibility of dangerous chemicals in the air, led to the evacuation of 1,500 people from their homes and businesses. The blast was reported at 4:30 P.M. and residents were allowed to return to their homes at about 9:30 P.M. 

Radio Iowa