(Updates with fatality) SALT LAKE CITY, Aug 16 (Reuters) - One of the rescuers attempting to find six miners trapped in the Crandall Canyon Mine has been killed following a cave-in, a Utah state official said on Thursday. Tammy Kikuchi, a spokeswoman with Utah's Department of Natural Resources, confirmed the fatality, and added that eight people had been injured. The cave-in was referred to as a "mountain bump" -- an eruption of rock and coal under increased pressure from overhead rock as drilling removes surrounding rock and material shifts in an area of the mine. The trapped miners have not been heard from since the central Utah mine caved in on Aug. 6. The Salt Lake Tribune reported on its Web site that three ambulances rushed to the mine, followed by three helicopters. Crandall Canyon Mine co-owner Robert Murray said earlier on Thursday the cavity found by a third bore hole had enough oxygen to sustain life indefinitely and that his crews would keep up efforts to contact the missing men. Rescue crews were preparing to drill a fourth hole into the mine on Thursday. Work on a tunnel that could eventually get them out was proceeding slowly because of seismic activity. It is not yet clear what caused the mine to collapse. Murray has said it was triggered by an earthquake despite disagreement from geologists.