The mining warden’s inquiry into the Moura No. 2 mine disaster found that the first explosion originated in a sealed mine panel (a block section of the mine) and resulted from a failure to recognise, and effectively treat, a heating of coal in that panel. The heating coal ignited methane gas which had accumulated within the panel after it was sealed. The inquiry did not reach a finding regarding the cause of the second explosion.
Read the Mining Wardens report into Moura No. 2 Mining Disaster here