Massive explosion after Baltimore train derailment

A video filmed by an onlooker showed the terrifying explosion after a cargo train derailed in a Baltimore suburb. 

As a fire rages around the wreckage of the derailed train, a man is heard to say "it's getting hotter too, so whatever it is, it's going to go." 

Seconds later, the person filming the video is knocked to the ground by the force of the blast. The sound of screams and screeching car tyres can be heard, as people who were moments earlier watching the spectacle desperately flee the scene. 

CSX Transportation, the cargo carrier that operates the train, said in a statement that one of the cars that derailed contained sodium chlorate, which is classified by the US Transportation Department as a hazardous material. 

Despite the scale of the derailment and the subsequent blast, reports suggests only one person was injured in the accident, believed to be the driver of a truck which collided with the train. That initial collision is thought to have triggered the derailment. 

The 50-year-old man was in a serious condition, according to a spokeswoman at a local hospital.