. >> it caught an oil well on fire with a horsehead pump that was several feet away from it.earn the train cars are carrying crude oil and ethanol. >> we went ahead and evacuated two miles downwind and a mile each side of it just to make sure that everybody was out of any kind of smoke cloud or anything else. >> huge flames spew from the super-heated inferno and thick dark smoke fills the sky. >> pan back. pan back. pan back. we just had a huge explosion. >> it really kind of surprised us, caught us off guard. >> suddenly, one of the train cars explodes in a gigantic plume of fire. >> just blew up. my god! my god! >> it was just unbelievable. i'm at 1,000 feet and i'm thinking this is not stopping. it just keeps growing and growing. pretty soon i'm looking out my door level with this huge mushroom cloud. >> the explosion was -- it was just pretty amazing. i haven't seen flames or smoke go that high before. >> the massive eruption catches firefighters by surprise. >> all of us just kind of looked up like wow. >> we heard it, we felt it. just the heat off of it was unimaginable