A multi-car crash on Interstate-29 became more dangerous after the accident when a wrecked truck carrying explosives began smoking. Sioux City police lieutenant Doug Young explains how they discovered the potentially explosive situation.He says the truck was towed to a nearby auditorium when they noticed it smoking and then discovered it was carrying explosives. Assistant Fire Chief John Clark says the Department of Transportation had towed the truck to do a routine inspection after the crash.He says the trailer had a broken axle and a missing set of wheels, and as they started inspecting the trailer, they noticed it was smoking. Clark says officers acted quickly to get everyone out of the way.He says they disconnected the power from the cab to the trailer, evacuate the trailer, and called for more help. Clark says they moved slowly to secure the trailer.He says they watched it with binoculars and called in the HAZMAT truck that has cameras with zoom lenses and a spotting scope so they could get a better look at the trailer. Clark says they determined the explosives in the trailer were not in danger of going off, so they called off the evacuation. He says a short in the wiring of the trailer had caused the smoke. Everything happened just before eight o’clock this morning.