The train derails and becomes a terrific wreck. Discovering the now highly unstable bomb on board, firefighters struggle to extinguish the fire at the crash site. After realizing that metallic sodium is on the train, the firefighters and NEST teams retreat to evaluate a strategy. In the meantime, all firefighting aircraft are grounded. The misinterpretation of a radio call to a water bombing helicopter leads it to dump its load of water onto the wreck. Water comes into contact with the metallic sodium, which explodes and in turn causes the nuclear bomb to detonate. The blast causes severe damage throughout Denver and releases an electromagnetic pulse. No cars work, electricity is out and anything with a computer is shut down.