There was stockpile of 1/2 materials and were having larger materials getting in stockpile and EE climbed up on stockpile to remove some of the wrong materials. Nearby is a highwall, and a rock, approx 10 inch long 2 inches thick came loose from highwall and fell, hitting EE's arm. No medical tx requested, on day of accident. 1/28/22 we found out EE went to ER for surgery.