The Strongman Mine (New Zealand’s largest state-owned underground coal mine) operated from 1938 to 2003. On 19 January 1967 a gas explosion in the mine killed 19 miners. An inquiry found that safety procedures had not been followed. In 1994 the original mine was replaced by the Strongman 2 mine further up the Nine Mile valley. The Strongman 2 mine closed in 2003.