On 27th of August 2020 at 08:37 am the rig was waiting for rigging up casing gears. The travelling block was parked at a height of approximately 4.7 mtrs. from the rig floor. Suddenly the block descended and rested on the rig floor. During this event, the fast line got removed from the fast line clamp and travelled through the fast line sheave and dropped to the rig floor. The fast line clamp was found lying close to the draw works on the rig trailer bed.