A devastating turn last night in the search for six miners still missing deep underground at a Utah coalmine. The search was abruptly halted after a second cave-in killed three rescue workers and injured at least six others who were trying to tunnel through rubble to reach them. All rescue workers were evacuated from the mine Thursday evening and work underground was stopped. Asked if the search would be suspended, "that's something to be determined," said Rich Kulczewski, a U.S. Department of Labor spokesman. The cave-in at 6:39 p.m. was caused by a mountain bump in which pressure can force chunks of coal from walls of the mine with great force.(