A cop dash cam records a propylene tanker explosion in the aftermath of the 2005 derailment and chemical leak of a Union Pacific train in Texarkana. The explosion caught on police car video involved seven empty train cars and a tanker containing flammable gas that rear ended another train. The explosion from the derailment killed one person and many had to evacuate nearby homes. The cop dash cam captures on video the huge explosion and resulting smoke. Watch as the police car has to back up quickly to escape the fire.