A propane bomb is a type of improvised explosive device which uses commercially available bottled gas cylinders, a kind of BLEVE. The devices have been used in terror attacks and school bombing plots.
A notable incident in which a propane bomb was used was during the Columbine High School massacre in which the two assailants Eric Harris and Dylan Klebold intended to kill students in the school cafeteria by using two 20-pound propane tanks fitted with timing devices. The bombs failed to detonate though one was partially detonated during the massacre.