An inquiry was under way Saturday after all four miners trapped by flash flooding in a colliery in Wales were found dead, plunging a tight-knit community into mourning. The body of the last of the four men was found Friday by rescuers who had battled treacherous conditions in the privately-owned Gleision Colliery mine near Swansea in south Wales. Phillip Hill, 45, Charles Bresnan, 62, David Powell, 50, and Garry Jenkins, 39, went missing on Thursday when flood waters broke through a retaining wall. Three other men with them managed to escape, but one was left in a critical condition. More than 24 hours after they first went missing, rescuers discovered the fourth body. All four were found in close proximity to one another near where they were working 90 metres (295 feet) below the surface. Authorities will now switch from a search and recovery operation at the flooded mine to an investigation into the incident, police said. Peter Vaughan, Chief Constable of South Wales Police, said: "We've tried to bring this safely to its conclusion. Unfortunately the conclusion we have is the one none of us wanted." Richard Smith, chief fire officer for Mid and West Wales Fire and Rescue Service, said: "It's a bit too early to tell whether they would have stood any chance of survival or not." The first body was found after divers sent into the mine could only proceed about 30 metres (100 feet) before having to turn back. Relatives huddled together in a nearby community centre then spent an agonising day hoping in vain for good news. The accident has shocked the tight-knit community in south Wales, once a coal mining heartland but where only a handful of collieries are still operating nowadays following the rapid decline of the industry in the 1970s and 1980s. Prayers will be said across churches in Wales this Sunday for the victims' loved ones, said the Archbishop of Wales Barry Morgan. The head of the Anglican Church in Wales, whose father was a miner, said the tragedy had moved the nation. "There was a time when there were mines across Wales -- and with them came accidents. We thought that those days were long gone," he said. "I hope they (the families) will gain some comfort from knowing that everyone in Wales is behind them. The whole community is heartbroken for them." Prime Minister David Cameron described the tragedy as "desperately, desperately sad". "It is clear the emergency services have done everything they can and worked incredibly hard," he said. "They haven't lacked for anything but it is obviously a desperately, desperately sad situation for everyone concerned. "The anguish of the families obviously is intense." Local MP Peter Hain said it was a "stab in the heart" for the community. "Everybody is rallying round but everybody is traumatised because they have not known this horror now for a generation or more," he said.