6L in the LOB when the EE placed their R-hand on top of the #7 S/C canopy. While leaning down talking to the operator a rock 12"" X 12"" X 4"" fell striking index, middle, and ring fingers. causing a laceration to all 3. They received 3 sutures in the index finger and 5 sutures in the ring finger. the area was 58"" high and approximately 19.5 feet wide.