Coal had been found near Kaitangata in the late 1840s, but commercial extraction did not begin until 1862, when William Aitchinson started pulling sub-bituminous coal from the ground. By 1872, Aitchinson and John Thompson of Balclutha had formed the Kaitangata Coal Mining Company to raise capital for expansion. Three years later, the company merged with the Kaitangata Railway Company to become the Kaitangata Railway and Coal Company Ltd, linking the mine directly to the rail network. Through 1875 and 1876, additional shafts were driven in anticipation of growing demand. By 1877, the company employed 41 men and aimed to produce 100 tons of coal per week. The mine was expanding fast, and oversight was not keeping pace.

The explosion sent dense smoke pouring from the mine entrance. Coal trucks were hurled from the drive. A boy named James Hawke, standing near the entrance, was blown several yards but survived. Initially, rescuers believed 36 men were trapped. Station master J. B. Griffen dispatched the company train to Balclutha to fetch Dr. Smith, who arrived 25 minutes later. Meanwhile, men from neighboring mines gathered as volunteers. Fire damp -- the methane that had been seeping through the tunnels for months -- initially prevented anyone from entering. W. Shore, R. M. Sewell, and Mr. Aitcheson were among the first to go in. A morgue was set up at Jenkin's hotel. By 1:30 in the afternoon, the rescuers had to withdraw because the air was too toxic. By seven that evening, they had recovered 24 bodies. Among the dead were fathers and sons: James Molloy alongside his two boys, John and Edward. William Hodge, the mine manager, was also killed. Twenty of the miners were married. Several had arrived just the day before, stepping off the steamer Wellington into jobs that would last them less than 24 hours.

The inquest that followed laid bare a pattern of negligence. Miner William Wilson testified that fire damp had been present in the mine since at least October 1878 and that, unlike English mines where old workings were bricked off and sealed, the Kaitangata mine left abandoned sections open. Miners used naked lights instead of the safety lamps standard in British collieries. Wilson believed the explosion originated in the old workings, where methane could accumulate undisturbed. Company director Allan Holmes admitted he had known about the gas since mid-1878 but said mine manager William Hodge had been casual about it. Safety lamps had been ordered in January 1879 -- one month before the disaster, and far too late. The jury found negligence. But the legal framework itself was broken: the Regulation of Mines Act 1874 was only enforceable if the provincial superintendent had proclaimed it in the New Zealand Gazette, and for the Otago province, no such proclamation had been made. The law existed on paper. Underground, it meant nothing.

The government moved quickly. On 28 February 1879, just one week after the explosion, a proclamation brought the Regulation of Mines Act into force throughout the entire country. Newspapers turned their scrutiny on the company directors, arguing that they had left Hodge to run the mine however he pleased and had never properly assessed his competency. Calls for more mine inspectors grew loud and persistent. The disaster also prompted a scientific debate: geologist Thomas Thompson Ritchie wrote to Dr. James Hector suggesting that gas had migrated through a cross-fault from the adjacent Shore mine at a lower elevation. Shore disputed this, arguing the distance was too great and that the real problem was the company's ventilation system, which had not been operational. Whatever the precise mechanism, the underlying cause was clear enough. Men had died because safety was treated as optional. In a gesture that speaks across the decades, Chinese miners from the Adam's Flat gold diggings donated to the relief fund for the miners' widows, giving an average of 10 shillings each -- solidarity from one group of laborers to another, in a colony that rarely extended them any.