On 24 November 1999, 65 miners in the North Parkes mine were undertaking maintenance. At approximately 2.50 pm, an ore body above the cave collapsed into a void causing an air blast, which travelled through the mine and damaged level one of the mine.

The blast resulted in the deaths of four workers. Workers in the other levels of the mine felt the effects of the blast, but were not injured.

The coroner Mr John Bailey released a report on 18 March 2003.