Environmental and Public Protection Cabinet
Methane explosion ruled cause of Darby mine accident
FRANKFORT, Ky. (Dec. 1, 2006) – An explosion that killed five Harlan County miners last May was caused by methane gas that had been ignited by an acetylene cutting torch, according to an accident report released today by the Kentucky Office of Mine Safety and Licensing (OMSL). Only one miner, Paul Ledford, survived the explosion at the Kentucky Darby No. 1 mine May 20.
State investigators believe two of the miners were using the torch to cut and remove a metal roof strap that intersected a seal in a return-air passage 3,200 feet inside the mine. The seal had been poorly constructed, according to the report, and was leaking methane.
Methane gas occurs naturally in a coal mine. Seals are constructed to block off inactive areas of the mine, preventing the methane in those areas from entering sections where mining is taking place. Leaking mine seals can create an explosive mixture of methane and oxygen.
Two of the miners, Amon “Cotton” Brock and Jimmy Lee, died in the explosion while three others died as they attempted to escape the mine. According to the Harlan County coroner’s office, Roy Middleton, Bill Petra and Paris Thomas died from carbon monoxide poisoning with smoke and soot inhalation.
OMSL’s report is based on information gleaned from interviews with Ledford, as well as testimony from 27 Darby employees who were subpoenaed and questioned by state investigators. The investigators also conducted physical examinations of the accident scene and reviewed the mine’s ventilation plan, payroll timesheets as well as purchase orders and bills of sale to provide information on construction of the seals.
Information obtained in the interviews and from the accident scene revealed the return-air seals were not built in accordance with Darby’s federally approved ventilation plan.
Nonconventional seals were constructed with lightweight, synthetic OMEGA blocks and were “dry-stacked,” meaning there was no mortar. Nor were the seals secured 6 inches into the mine floor as required by the ventilation seal plan approved by the federal Mine Safety and Health Administration (MSHA). The investigation revealed the individuals assigned to build the seals were not familiar with the MSHA-approved seal plan.
Investigators found oxygen tanks, the acetylene torch and a torch striker scattered across the blast area where the return-air seal had been located. Evidence at the scene indicated a portion of a metal roof strap that had intersected the return-air seal had been cut with a torch. Acetylene torches or any ignition sources are prohibited in the return-air course of a mine.
According to statements from Ledford, he and the other three miners who survived the explosion donned Self-Contained Self Rescuers (SCSRs) and attempted to exit the mine. When their four-wheel buggy became stuck on mine debris, the men attempted to walk out of the mine by following a power cable. The escape was made difficult by dense smoke, equipment, coal and rock debris scattered along the exit way.
Preliminary test results of the SCSR units revealed the units worn by the four miners did produce oxygen. The four miners became separated and Ledford was found by the mine rescue team approximately two hours after the explosion.
Three days after the Darby accident Governor Ernie Fletcher ordered OMSL to require daily inspections of all nonconventional seals for a seven-day period. As a result, at least five mines were closed after inspections revealed improperly built or leaking seals.
Governor Fletcher also directed OMSL to issue a safety awareness bulletin requiring coal companies to follow proper testing and inspection procedures for all SCSR units. OMSL analysts began visiting every underground mine in the state to meet with miners to inspect SCSR units. As a result, 134 damaged SCSR units were removed from service and replaced by coal companies.
The OMSL report is available online at www.EPPC.ky.gov; www.DNR.ky.gov and www.OMSL.ky.gov