A car bomb exploding at a US Army range. The bomb was detonated to show the effectiveness of plastic explosives as used by various terrorist groups. The bomb contained 500g of Comp C-4 explosive, similar to the more famous Semtex. This photograph was taken shortly after detonation. The steel roof of the car is seen flying through the air at the top of the frame. The pressure wave from the explosion travels initially at 9, 500 metres per second. A bomb roughly of this size was used to destroy a Boeing 747 of Pan American Airlines over Lockerbie, Scotland, in December 1988 causing the loss of 270 lives. The Semtex for that bomb had been packed into a small tape recorder.