The shearer operator was kicking spilled coal from the walkway when he slipped and fell in front of the chock.

The chock advanced and crushed him against the AFC pan line.

The shearer had just completed the snake cut at the tailgate and was returning to the tailgate end.

Chock movement control was automatic, initiated by the shearer as it proceeded along the face. The chock had been primed to move when the operator slipped and fell in front of it.

The gap between the front of the chock and the pan line was sufficiently narrow that the potential for a person to receive fatal injuries was high, according to the New South Wales Department of Primary Industries.

The department said to avoid a similar incident operators should review their work procedures with an emphasis on identification and implementation of hard barriers to prevent access of longwall personnel into hazardous areas and safe standing zones for shearer operators for each mining sequence across the face.

The DPI said longwall personnel should have safe access along the face at all times and regular audits should be made to ensure compliance with work procedures.