The crowded 6.09 am commuter train from Mount Victoria in the Blue Mountains to Sydney left the rails, and hit a support of an overhead road bridge constructed from concrete and steel. The bridge, and several cars which were on top of it, crashed down on top of several carriages, crushing them.
In all, 83 people died and many others were badly injured.
Recently, an Australian movie was made of the disaster, titled 'Day of the Roses'.