The disaster at the Gleision mine in South Wales began when miners blasted underground.
A wall holding back water collapsed—and thousands of gallons flooded the shaft.
The seven miners inside scrambled for safety.
But four miners—David Powell, Garry Jenkins, Phillip Hill and Charles Breslin—were trapped almost 300 feet below ground.
Their bodies were later found one by one.
The Gleision mine, which reopened in 2009 in response to a surge in commodity prices, is a drift mine. Coal is extracted using near horizontal tunnels.
Owners were recently given planning permission to mine fresh seams deeper into the hillside.
The coal seam is just 76cm high, and those who work in it must kneel or lie down.
The mine uses wooden props to reinforce the tunnels, though these were abolished in state mines half a century ago.
The miners earned about £500 per week—for working underground for ten hours a day.
Gleision is typical of the smallest drift mines, which are often owned by individuals rather than big companies.
They have opened and shut regularly over the past 50 years as commodity prices rise and fall.
The National Union of Mineworkers (NUM) is worried that these privately-controlled facilities operate largely “under the radar” of mine inspectors.
Chris Kitchen, general secretary of the NUM, said, “We fear that safety is often set at minimum standards so that costs can be kept down. They are not generally unionised or easily visited by inspectors.”
The 1973 Lofthouse disaster in West Yorkshire trapped seven miners. This led to a code of practice to try to stop cases of a dangerous inrush of water.
The NUM wants to know now whether that code was operating in South Wales.
For those working in small private mines like Gleision, many of the dangers that miners faced centuries ago remain.
The Health and Safety Executive (HSE) said it couldn’t discuss details during an investigation. The colliery had been due an inspection from HSE later this year.
The inquiry is likely to focus on why the men were working in a part of the mine which was clearly marked on maps as being close to underground water.
Plans of the mine suggested the men could have been working in a section that was not licensed for mining.
Gleision is understood to have been in financial trouble in recent months.
Construction Safety Campaign national meeting: Saturday 26 November, 12 noon to 3.30pm at Shakespeare Hall, North Rd, Durham, DH1 ASQ. Go to firstname.lastname@example.org