A Colorado-based engineering firm has been hit with a hefty fine for its culpability in the 2007 Crandall Canyon mine disaster which left nine people dead.

Agapito Associates Inc., based in Grand Junction, Colorado, has been ordered by the federal Mine Safety and Health Administration (MSHA) to pay a fine of $100,000 for its failure to properly observe mine safety laws in the lead up to the 2007 Crandall Canyon mine disaster.

The settlement reached by MSHA, which still awaits judicial approval, should bring a conclusion to legal proceedings launched by the federal government in relation to the fatal incident.

The disaster commenced on August 6, 2007, when a six-man crew was left buried by the bursting of walls along a lengthy tract of underground tunnels in the Emery County coal mine.

Another implosion occurred 10 days later, this one affecting a team of rescue personnel attempting to retrieve the stranded miners.

The disaster occasioned the deaths of the six miners involved in the initial collapse as well as three rescue workers hit by the second collapse.

MSHA investigators have since found that Agapito was at fault for a dangerous mine design after performing a defective engineering analysis of the mining zone situated below East Mountain, and was guilty of a “high-negligence violation” of mine safety laws.

As a result of its flawed assessment, the mine’s roof-supporting coal pillars were too small to support the overlying mountain as crews engaged in a hazardous mining practice known as “pulling pillars,” which involves the excavation of pillars as miners withdraw from the mine, triggering the collapse of the roofs to their rear.

MSHA leader Joe Main said that the fine would bring final closure to the case, with Agapito bearing its fair share of culpability.

“With this settlement, Agapito takes responsibility for its role in the tragic mine collapse at Crandall Canyon,” he said. “When you look at the size of the penalty for a contractor and the fact they have agreed to a high negligence finding, that’s a sizable end result for the closure of this case.”

An official investigation launched by MSHA into the causes of the disaster had previously laid most of the blame at the feet of Genwal Resources, the mine‘s operator and co-owner, which was a subsidiary of Ohio-based Murray Energy Corp. The company agreed to pay $950,000 in civil penalties in September 2012.

Genwal was also fined $500,000 by the US District Court for Utah after pleading guilty to two criminal dismeanours for wilful violation of federal health and safety requirements.