On 23 March 1887 at 2.30 pm, a flame from an oil safety lamp ignited marsh gas or carbonic hydrate that had accumulated at the face of the Bulli Colliery coal mine. Eighty-one miners were killed in the resulting explosion.

Although the mine was renowned for having above average concentration of methane gas in specific areas, it had become normal practice for miners to unlock safety lamps.

An inquiry found that a lack of regulation and care for safe work practices were responsible for the methane gas blast.