Facing the Multiple Risks of Newer, Deeper Mines

As hope dims for the six miners trapped by a coal mine collapse in central Utah, engineers and seismologists are grappling with the broader implications of the Crandall Canyon Mine accident and the interplay of risks they say are mounting in the newer, deeper generation of coal mines, especially in the West.

The extreme depth of the mine, the history of mining-induced seismic activity in Utah
Whether and how any of those factors combined to set off the huge structural failure inside the mine on the morning of Aug. 6, a movement of earth so intense that it measured 3.9 in magnitude and was first thought to be an earthquake, is unknown. Officials at the federal Mine Safety and Health Administration said they would not formally begin their investigation until the rescue or recovery efforts were completed.

But there is little doubt, mine experts said, that retreat mining at extreme depth in Utah, where mine-produced tremors are common, creates a tapestry of forces that adds to mining