The coroners service says the 59-year-old water truck driver from Coleman, Alta., was filling his truck with water at the Sparwood, B.C., mine when he was hit by falling rock.
Lorenz was taken to a hospital in Alberta, but he could not be resuscitated.
B.C.'s Mines Ministry said in a written statement issued Sunday that no other workers were injured.
The coroners office says it is investigating the death along with the RCMP and the provincial inspector of mines.