Three rescue workers were killed and at least six others injured when a section of Utah’s Crandall Canyon coal mine caved in Thursday night. The workers were involved in the nine-day effort to reach six miners trapped deep within the mine. Seismic activity has caused the operation to halt several times; a seismic “bump” caused the latest collapse. The injured included two officials from the federal Mine Safety and Health Administration. “The seismic activity underground has just been relentless,” said Bob Murray, head of Murray Energy Corp., which co-owns the mine. “The mountain is still alive, the mountain is still moving, and we cannot endanger the rescue workers as we drive toward these trapped miners.” As of last night, all rescue workers had been evacuated and the operation put on hold. “It’s a devastating blow to what was already a tragic situation,” said Joe Piccolo, the mayor of nearby Price. “It’s a very stressful part of the way of life that’s been known here for years.”