A major rescue operation was under way last night to free four miners trapped in a flooded colliery.
Three other miners managed to escape as rising water engulfed a drift mine at Gleision Colliery in Pontardawe, near Swansea, yesterday morning. Two of the workers were helping with the rescue last night; another was being treated in hospital and was said to be in a critical condition.
Rescue efforts were hampered by water seeping into the colliery. A parallel tunnel was being used to pump oxygen into the horizontal shaft where the men were trapped 90m (295ft) below ground, while also trying to pump the water out. Last night divers were sent into the mine to investigate conditions below the surface.
The trapped men were named by police as Phillip Hill, 45, David Powell, 50, Charles Bresnan, 62, and Garry Jenkins, 39. Police said emergency services were conducting a "multi-agency rescue operation" and the men's families were being supported by family liaison officers.
Despite not having had contact with the miners since the rescue began, crews said they were "hopeful and optimistic" that they would be freed.
Chris Margetts, of South Wales Fire and Rescue Service, said: "There are numerous little tunnels and old workings which all potentially have air pockets in. The conditions down there are favourable. It's not raining [and] there is water at the bottom but the air supply is good. They are experienced miners and know the layout of the mine. They would know where to go."
The alarm was raised shortly after 9.20am, when police helicopters and rescue teams were called to small, private hillside mine, which has been in operation since 1993.
A retaining wall holding back a body of water underground failed, flooding the tunnel the seven men were in. About 50 people were thought to be helping with the rescue, with teams coming from as far away as Yorkshire.
Superintendent Phil Davies said the emergency services were involved in a "difficult rescue operation". "There is not a blockage issue in the mine; it is a water issue which we are trying to drain. It is a difficult and dynamic rescue situation but everybody who needs to be there is there," he said, adding that an investigation into the causes of the accident would be launched.
Police, fire and ambulance crews were present last night and anxious families were being kept informed at a nearby community centre.
David Cameron, returning from his trip to Libya, pledged that "every support" would be given to the emergency services. The First Minister of Wales, Carwyn Jones, praised the rescue teams, who were working "in very dangerous and difficult conditions".
"We know that water is ingressing into the mine. The mine itself is underneath quite a steep slope near the River Tawe," Mr Jones added. "My main priority and the priority of my government is to ensure that those trapped are rescued as quickly and as safely as possible."
Mining accidents in Britain are rare, but the industry is not without danger. Seven people have been killed in mining accidents since 2006.Reuse content