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Work far from over at flooded mine site

SOMERSET, Pennsylvania (CNN) -- The rescue of nine men at Pennsylvania's Quecreek coal mine hasn't brought work to an end at the site.

CNN NewsPass Video    •  CNN's Jeff Flock visits an abandoned Pa. mine   •  Surveyor used GPS to locate miners   •  Rescued miners go home   •  Miners express appreciation  MORE STORIES   •  Pennsylvania panel to explore mining accident   •  Flooded mine could be idle for months   •  Pa. governor: Mine's operator 'owes answers'   •  A turning point in the rescue effort   •  Miners braved harrowing conditions   •  Previous mining accidents were minor » Story archive  RESOURCES   •  Jeff Goodell: Despair turns to joy   •  Gov. Schweiker: Mine probe to seek answers   •  Rescued miner: 'It was a team effort'   •  Why we burn coal  EXTRA INFORMATION   •  Gallery: The rescued miners   •  Gallery: Rescue quotes   •  Graphic: Diagram of the Quecreek Mine   •  Map: Mining accident   •  Timeline: What happened, and when

In addition to cleaning up the spot where the miners were hauled back to the surface of the earth early Sunday, officials will investigate the cause of the accident, which apparently happened when the miners relied on a map that inaccurately depicted the location of an abandoned, water-filled tunnel.

The investigation would center on what was wrong with the maps and why, said Dave Hess, secretary of Pennsylvania's Department of Environmental Protection.

The miners were digging in the Quecreek coal mine Wednesday night when a wall separating their tunnel from a nearby abandoned, flooded mine gave way, sending millions of gallons of water roaring into Quecreek.

Doug Custer, a miner who escaped when the others were trapped, blamed faulty maps for the accident.

"I think the maps were wrong back in the olden days," he said. "I think that they were advanced further than what it showed."

Dave Lauriski, director of the U.S. Labor Department's Mine and Safety Administration, said certain standards should be followed when approaching old mines.

"We need to understand if those came into play here," Lauriski said.

A team of investigators was being assembled to conduct interviews, examine records and crawl into the Quecreek mine once all the water has been pumped out to try to prevent similar accidents.

Betsy Mallison of the Department of Environmental Protection said workers would continue pumping out water that rushed into the mine, which officials estimated was about 50 million gallons.

"There's still water in that mine, and there's still work to be done," Mallison said. "And the reason for that is there's still equipment down there."

Officials haven't decided if they will permanently shut the Quecreek mine, but the rescue shaft that dug through 240 feet of earth and rock will be closed, said Mallison.

"You just push a cement kind of substance down into the hole, and then you're done," she said, describing the process.