This paper serves to outline the circumstances and causes of the air-blast that occurred at Northparkes Mines in November 1999. It describes the design of the mine, the geotechnical issues surrounding cave propagation and the cave monitoring systems that were in place prior to the event. A short description of the air-blast that followed a sudden collapse is given. Details of the risk assessment process that evolved during the rectification process are provided with their subsequent modification to form the core of a major hazard monitoring process. The system is in line with the recommendations given by the Coroner resulting from the inquest into the deaths of the four people who lost their lives during the air-blast._x000D_
FORMAL CITATION:Ross, I and van As, A, 2005. Northparkes Mines - design, sudden failure, air-blast and hazard management at the E26 Block Cave, in Proceedings Ninth Underground Operators' Conference 2005, pp 7-18 (The Australasian Institute of Mining and Metallurgy: Melbourne).