On 13 June 1989, exceptionally heavy rain caused strong flows in the creek system to the south and east of the EMU mine situated in Leinster. Water in the 450 south pit adjacent to the operating mine began to rise as the blocked creek system backed up and began to spill over into it. At the same time, the main AG pit began to fill with water.

The mining crew made preparations to vacate the decline but had re-entered it to retrieve a pump when the neck of ground separating the pits began to erode rapidly, vastly increasing the rate of water flow into the AG pit. The manager drove into the pit and down into the decline to evacuate the five men, however, all six men drowned