On Tuesday, 18 January 1977 at Granville, a western suburb of Sydney, New South Wales, Australia, a crowded commuter train led by a 46 class locomotive derailed, running into the supports of a road bridge that collapsed onto two of the train's passenger carriages.
While the official inquiry found the primary cause of the crash to be poor fastening of the track, there were a number of factors that were identified as contributing to the accident.
It remains the deadliest rail disaster in Australian history; 83 people died and 213 were injured. An 84th victim, an unborn child, was added to the fatality list in 2017.
The train involved in the disaster consisted of eight wooden bodied Supplementary Interurban Passenger Carriages, which had been converted from country passenger stock by the PTC, hauled by 46 class electric locomotive 4620. It had commenced its journey towards Sydney from Mount Victoria in the Blue Mountains at 6:09 a.m.
At approximately 8:10 a.m. it was approaching Granville railway station when the locomotive derailed and struck one of the steel-and-concrete pillars supporting the bridge carrying Bold Street over the railway cutting.
The derailed engine and first two carriages passed the bridge, with the first carriage being separated free from the other carriages and torn open when it collided with a severed overhead stanchion from beside the track, killing eight passengers instantly.
The remaining carriages (cars 2 to 8) came to a halt with the second carriage clear of the bridge, and the rear half of the third carriage, along with the forward half of the fourth carriage, coming to rest under the weakened bridge, whose weight was estimated at 570 tonnes (560 long tons; 630 short tons). Carriages 5, 6, 7 and 8 were clear of the bridge at the Harris Park (or country side) of the bridge and were not harmed besides minor injuries and the shock of having been involved in the incident.
Within 15 seconds, with the majority of its supports demolished, the bridge including several motor cars that were driving across at the time, collapsed on top of the carriages, demolishing their wooden bodies and crushing the passengers inside.
Of the total number of passengers travelling in the third and fourth carriages, half were killed instantly when the bridge fell on them, crushing them in their seats, some to the point their heads and shoulders were below the level of their knees.
Of the 213 injured, several were trapped for many hours after the accident had occurred, with parts of the bridge, the carriage body and broken seating, or deceased passengers crushing them, hampering rescuers. Some of those trapped remained conscious and lucid, speaking to rescuers and recounting their experiences of the event, however, most of them died of crush syndrome soon after the weight was removed from their bodies.
Rescuers also faced the greater difficulty of the weight of the bridge, which was still crushing the affected carriages and reducing the available space in which they could work to rescue survivors. At one stage of the rescue, a declaration was made by those in charge that no further rescue attempts were to be permitted until the collapsed bridge had been lifted clear of the site. Soon after, the bridge settled a further 5 centimetres (2 in) onto the train, trapping two rescuers and crushing a portable generator "like butter".
Another major danger came from Liquid Petroleum Gas, as LPG cylinders were being kept year-round on board the train to be used in the winters for heating purposes.
Several of the deceased were overcome by the gas leaking from ruptured cylinders, reducing the amount of available breathable air in the area underneath the bridge. This leaking gas also prevented the immediate use of rescue tools such as petrol powered saws and cutting equipment, due to the risk of explosion. The NSW Fire Brigade provided enough ventilation equipment to dispel the gas, as well as a constant mist/film of water, sprayed over the accident site to mitigate the risk of the gas ignition.
Train driver Edward Olencewicz, assistant crewman Bill McCrossin (the "second man"), and the motorists (including one motorcyclist) driving on the fallen bridge all survived.
The operation lasted from 8:12 a.m. Tuesday until 6 a.m. Thursday. Ultimately, 83 people were killed in the crash.
The Bold Street Bridge was rebuilt as a single span without any intermediate support piers, and other bridges similar to the destroyed bridge had their piers reinforced.
The original inquiry into the accident found that the primary cause of the crash was "the very unsatisfactory condition of the permanent way", being the poor fastening of the track, which has caused the track to spread and allowed the left front wheel of the locomotive to come off the rail.
Other contributing factors determined during investigation included the structure of the bridge itself, the condition of the track, and the condition of the locomotive.