> a train carrying propylene, a highly flammable petrochemical used in manufacturing blows up in texarcana, arkansas early in the morning, october 15th, 2005. a police car's dashboard camera captures the massive explosion. with no time to turn around, the officer throws his car into reverse and races backwards to escape the growing river of fire coming right at him. >> it was quite massive. just as far as you could see, just nothing but flames. >> the disaster starts when officer randy mcadams is finishing up the night shift. a moving freight train hits a parked train at the texarcana depot, causing a derailment but not an explosion. >> could you call back and see if they can ascertain exactly which car is overturned and maybe what the contents of the car was? >> it's not like a regular car accident. it can be thousands of gallons of very toxic chemicals up to maybe nothing leaking at all. kind of have to get there and investigate and determine what's going on. >> officer mcadams is one of the first on the scene. >> i've got some kind of chemical smell. i'm backing up. it's slowly drifting