route. >> a few minutes after the collapse, the remaining gasoline burns off and the flames begin to diminish. once the blaze is under control, firefighters can assess the damage in terms of material and lives. >> there was only one fatality which was the driver of the gas tanker that lost his life. i thought there would be worse. that time of day on the interstate, 12:30 on a friday afternoon, july, vacation to the mountains, i figured there would be three or four cars underneath it. >> the interstate remains closed for nearly four days as cleanup crews deal with the rubble and runoff gasoline. ultimately, the bridge is rebuilt. and summer traffic resumes. as does the danger found in the twists and turns of this infamous four-mile stretch of highway. coming up -- a chemical plant is destroyed. >> we headed toward what looked like a little hiroshima cloud.