Employee stated EE parked the diesel scoop at the new #1 unit setup area in #8 entry between spad 11+90 and 12+60 when a piece of rock 4""x9""x1/2 to 2"" thick fell from the edge of a kettle bottom. EE was located more than 2500' off the active working section #3 unit. This area had been worked out in Jan. of 2021.