MONTCOAL, W.Va. — Two full days after the worst U.S. mining disaster in a generation, dangerous gases underground prevented rescuers late Wednesday from venturing into the Upper Big Branch coal mine to search for any survivors of the explosion that killed at least 25 workers.
Crews drilled holes deep into the ground to release the gases. By evening, a federal safety official said the levels of lethal carbon monoxide and highly explosive hydrogen and methane measured at the top of the holes were steadily dropping.
Officials could not say specifically when rescuers might be able to go in, but if the readings at the bottom were good, they want them on the move as soon as possible.
