Transcript for Train Derailment and Massive Explosion in Baltimore
And we turn next to that mysterious explosion after a freight train collided with a truck today outside baltimore, maryland. It was so powerful, it could be felt blocks away. And eyewitnesses said buildings shook, windows shattered. Abc's david kerley is right there. David, that's the smoke I see behind you? Reporter: It is, absolutely. Firefighters just started pouring water on it again, the burning railcars. Plenty of smoke. This started at 2:00. A truck driver is in serious condition. And wait until you see this explosion right after the derailment. Reporter: Two railcars burst into flames after derailing. But as the fire intensifies, a massive explosion. Back up. Reporter: Two warehouses had their walls shredded, windows blown out in the surrounding area. People in a 20-block area told to stay away. I thought it was an earthquake cause the house shook. It wasn't just a normal boom. When it went, it knocked me down and my two other co-workers. Reporter: Here it is again, the blast that intensified the fire. Officials say a garbage truck that hauls dumpsters, hit the train. 15 cars in all derailed. The rail company says there are no dangerous inhalents. The burning cars carry acid. Another car is filled with a hazardous chemical that can be explosive. This is the third serious derailment this month. Friday night in missouri a train took out the supports for an overpass. And rail lines snake through every major city, and many neighborhoods, like the one on fire tonight. David kerley, abc news, rosedale, maryland.
This transcript has been automatically generated and may not be 100% accurate.