Safety concerns shut Signal Peak mine

摘要

The Signal Peak underground coal mine in Montana was temporarily shut down yesterday after carbon monoxide reached dangerous levels. Carbon mono_xide reached more than 125ppm in a previously mined area about 1.7 miles from where miners were working. Mine Safety and Health Administration (MSHA) standards require that any reading above this level be reported, and Signal Peak chose to shut down operations as of 2:15pm MT (4:15pm ET).