Stronger seals, proper methane monitoring and the removal of a pump cable from a sealed area underground could have prevented the Sago Mine disaster, according to a report issued Wednesday by federal investigators.

U.S. Mine Safety and Health Administration investigators identified these as "root causes" that, if eliminated "could have mitigated the severity of the accident or prevented the loss of life," according to 190-page report.

MSHA officials did not cite mine owner International Coal Group for these problems — or any of the 149 violations they found in their Sago investigation — as violations that contributed to the Jan. 2, 2006, disaster.

MSHA pointed to a lightning strike as the "most likely" ignition source for the explosion that ripped through a sealed area of the Sago Mine, killing 12 workers and seriously injuring another in West Virginia's worst coal-mining disaster in nearly 40 years. Based on a report by the Sandia National Laboratory, MSHA investigators concluded the lightning created an electromagnetic field, which created enough energy to induce a voltage onto a pump cable that mine owner ICG had left in the sealed area of the mine. In turn, this voltage, the theory goes, would cause an arc or spark that ignited methane built up inside the sealed area.

Also, MSHA said bottom mining of the sealed area’s floor created a funnel that prompted “drastic increases” in the explosive forces as they reached – and eventually pulverized – the lightweight, foam-block seals ICG had installed. However, even properly built seals might not have withstood the 93-psi blast described in the report.