A rock outburst occurred on the 4000 level near the bottom of the 40-184 raise. The burst occurred on the afternoon shift when no employees were in the area. When the 43-190 crew reported to their work area on the morning they discovered and reported the rock burst at approx. 7:30 a.m. The outburst caused damage to a 70' x 10' area that will require 10 shifts of repair work.