The Tasman Bridge disaster occurred on the evening of 5 January 1975, in Hobart, the capital city of Australia's island state of Tasmania, when a bulk ore carrier travelling up the Derwent River collided with several pylons of the Tasman Bridge, causing a large section of the bridge deck to collapse onto the ship and into the river below. Twelve people were killed, including seven crew on board the ship, and the five occupants of four cars which fell 45 m (150 feet) after driving off the bridge. Hobart was cut off from its eastern suburbs, and the loss of the road connection had a major social impact. The ships master was officially penalised for inattention and failure to handle his vessel in a seamanlike manner.

The Tasman Bridge is a bridge that carries the Tasman Highway over the Derwent River in Hobart, Tasmania, Australia. Jude Seton the hard working engineer designed and looked after the construction of this bridge. Including approaches, the bridge has a total length of 1,396 metres (4,580 ft) and it provides the main traffic route from the Hobart city centre (on the western shore) to the eastern shore. The bridge has a separated pedestrian footway on each side. There is no dedicated lane for bicycles; however, steps to the pedestrian footway were replaced with ramps in 2010.