At approximately 10:24hrs on 10thFebruary 2020, running in hole milling bottom hole assembly was in progress. Assistant driller was on the brake and a floor man was operating the power tong to disengage. During this time the Assistant driller released his hand from the brake handle and stretched himself out of the driller’s cabin for better view. As a result the work string moved up and the power tong was pulled along with it. This resulted the support arms of the power tong to break and power tong slid back to the tool joint.