Alpha miner killed in Greenbrier CountySHINNSTON, W.Va. -- Divers looking for a man whose bulldozer fell into a coal slurry pond when an embankment collapsed on Friday are being hampered in their search because the material in the pond is so thick.Crews located the bulldozer in the pond on Saturday evening, and planned to send divers in today. But U.S. Mine Safety and Health Administration spokeswoman Amy Louviere said this morning that divers probably wouldn't go in today.The bulldozer and two pickup trucks slid into the Nolans Run impoundment of Consol Energy's Robinson Run mine shortly after noon Friday. Two engineers who tumbled into the water were promptly rescued. They were treated at hospitals and released.Lynn Seay, spokeswoman for Pennsylvania-based Consol, said in an email that the bulldozer was located early Saturday evening."The dive crew is currently trying to determine the depth of the dozer,'' Seay wrote. "Once that determination is made, the recovery operations will stop for the night to allow for development of a recovery plan and will resume in the morning.''She wrote in a subsequent email, "We cannot yet determine if our employee is in the cab of the bulldozer and will not know that until we proceed with the recovery plan.''Earlier, Seay said the search for the missing worker had been suspended at midnight Friday and resumed Saturday. Crews were draining the pond, which was 12 feet deep, and sonar equipment was brought in to help divers and other rescue personnel who were searching for the missing person. Seay said the embankment remained unstable and continued to shift, creating difficult conditions for the search.The Robinson Run mine was idled while the search was under way, and Seay said a decision on resuming operations would be made on a shift-by-shift basis.U.S. Mine Safety and Health Administration officials were on site, along with company, state and union officials. It was unclear what caused the collapse, which MSHA spokeswoman Amy Louviere described as a "massive failure'' at the mine's preparations plant.Preparations plants wash raw coal to help it burn efficiently before it is shipped to customers. Coal slurry impoundments are used to contain both solid refuse and the wastewater byproduct known as slurry.The accident occurred on the same day that an electrician, Steven O'Dell, 27, of Mount Nebo, was killed when he became caught between a scoop and a continuous mining machine at a White Buck Coal Co. mine in Greenbrier County. The company is a subsidiary of Virginia-based Alpha natural Resources.O'Dell is the state's sixth mining fatality this year.