Did Quake Cause the Utah Mine Collapse?

This week's tragic coal-mine collapse in Utah has become the focus of an argument between scientists studying the event and executives at Murray Energy Corp., the company that owns the Crandall Canyon mine. On Monday, University of Utah seismographs recorded shaking near the mine that registered 3.9 on the Richter Scale, and 10 smaller aftershocks over the next day.

The company says the initial quake is what caved in the mine, but seismologists are arguing that the data suggests it was the other way around. They contend that a natural earthquake has a different seismic signature than the shaking produced by a cave-in, and that the data they picked up is more consistent with the latter scenario. Murray Energy, meanwhile, insists that the event was a natural disaster, and that they can prove it. —Gregory Mone