Napalm bomb production. 1950s production of a napalm bomb at Rocky Mountain Arsenal, Commerce City, Colorado, USA. Napalm is a flammable liquid that sticks to the skin and causes severe and often fatal burns. It usually consists of a gelling component mixed with gasoline (petrol) to produce a flammable liquid used as an incendiary weapon. Rocky Mountain Arsenal, used to produce a range of chemical weapons, was constructed during World War II. It was operated by the US Army until it closed in 1992. Photographed by a Denver Post photographer on 2 August 1957.