West Gate Bridge
Problems were first noticed on the West Gate Bridge in May 1970 when several steel girders did not fit into position by about . Engineers proposed putting ten concrete blocks, each weighing about 8 tons, onto the girders to bend them into the correct position. In September 1970 it was noticed that this had caused part of the girder to buckle. On 15 October, the engineers began removing the bolts holding the buckled girders in place. This would allow the steel to unbuckle and new steel could be put up to support the damaged section. At 11:50 am the damaged section collapsed. Workers both on and under the bridge were killed when the 2,000 ton section fell  to the ground. In the end, 35 men were killed and 18 were injured.