The four miners are trapped at Gleision Colliery in the Swansea Valley. Three other men managed to escape as water rushed into the small mine. One of them was taken to hospital where his condition is described as “critical”.
The four trapped have been named as Phillip Hill, 45, from Neath, along with Charles Bresnan, 62, David Powell, 50, and Garry Jenkins, 39, all from the Swansea Valley.
Prime Minister David Cameron, who is returning from a trip to Libya, said tonight that “every support” would be given to the emergency services, who had still not made contact with the men.
“My thoughts are with those missing and their family and friends at this very difficult time,” he said.
Chris Margetts of the South Wales Fire and Rescue Service said: “the miners are located approximately 90 metres underground. They are down a 250 metre (820ft) main route into the mine.” He said that there could be numerous potential air pockets in tunnels and old workings, adding: “They are experienced miners, they know the layout of the mine they would know where to go in this situation.”
Rescuers are pumping out water in an attempt to clear the exit from the mine but described the dry weather conditions as “favourable” and the air supply as “good”.
A Welsh Government spokesperson said: “The First Minister is being kept fully aware of the incident and the ongoing multi-agency response. Clearly, at this stage, our thoughts are with the individuals involved, and their families at this very difficult time.”
The pit, which is a drift mine, works coal under a very steep hillside above the banks of the river Tawe in Cilybebyll near Rhos.
It was reported in 2001 that there were about seven men at Gleisoion, including the mine owner who himself worked underground. It was also reported that it is a safety lamp mine with severe water problems which require the use of a powerful sump pump.
It is said the combined problems of water and gas can cause disruption to production and development. Production was reported as being about 200 tonnes per week.