Some pointed out that officials from the Sago Mine had been on the scene after the explosion there trapped 13 miners, killing all but one.

In 2005, the Sago Mine had only one violation concerning its oxygen equipment, according to federal records.

Anker West Virginia Mining was listed as the permittee for the Sago Mine.

Mining operations at the Sago Mine more than doubled between 2004 and 2005, and the injury rate was significantly above the national average.

Before the January disaster at the Sago Mine near here, where 12 miners died, the operator had been cited 273 times since 2004.

Just down the road near the entrance to the Sago Mine, 12 black ribbons hung from a fence.

Among the six coal mines it serves is the Sago Mine, site of the Sago Mine disaster in 2006.

But many large mines, including the Sago Mine, rely on blocks made of dense foam, which are lighter, easier to move and cheaper.

The cause of the latest incident, which claimed 12 lives at the Sago Mine in West Virginia, is unknown and under investigation.

The Sago Mine had 202 safety violations last year, a number that included 16 blatant violations that were considered immediate hazards to miners' safety.