A report has revealed that an underground explosion that killed five Kentucky coal miners last spring was caused by a preventable methane leak, the use of a cutting torch and other mine violations. The state investigative report, which was released last month, was bad news for the mine operators. Methane had leaked from a “poorly constructed” protective seal at Kentucky Darby LLC, No. 1 mine in Harlan County, according to the report. The seal was one of two at the mine that were supposed to keep combustible and poisonous gases underground, but neither met federal guidelines.

The gas was ignited by an open-flame torch used by two of the victims, mine foreman Amon Brock and maintenance worker Jimmy Lee, who were making repairs to metal straps used as underground roof supports. The straps intersected the top of the seal, leaving room for a leak and serving as heat conductors. The report also said Brock and Lee shouldn’t have been allowed to use a torch at the site of the repairs because that section of the mine was in the “return air course,” which is the ventilation current that passes through active mine areas and is returning to the surface.

According to witness testimony, Mr. Brock had said they had to make repairs to the area before a federal inspector from the U.S. Mine Safety and Health Administration, who was inspecting the mine the week of the explosion, returned to the site two days later. Both Brock and Lee died at the site of the explosion from blunt force trauma and heat injuries. The other three victims died from carbon monoxide poisoning and smoke inhalation while trying to escape. A sixth miner was rescued with minor injuries. The federal report by MSHA is expected to be released by March. Other major findings listed in the state’s report are as follows:

• In March, Darby mine examiner Tom Lunsford notified mine boss Ralph Napier that metal roof straps were present where the seals were to be constructed later in the month. Napier allowed the seals to be built anyway.

• During seal construction, the fiberglass blocks used were “dry stacked” without adhesive and were not secured properly to the mine floor, which violated the ventilation plan. The sealant that was sprayed over the seal also was not approved by MSHA.

• The torch found at the explosion site had its fuel and oxygen valves turned toward the “off” position. However, both valves were still positioned to release fuel to the torch.

It’s difficult to understand why safety continues to be ignored in many coal mining operations around the country. I’m not sure what it will take to change things in that regard.