The hook from the tubular pull back tugger in the derrick fell to the drill floor while tripping out of the hole. The tugger hook was of a design with a clevis pin through the hook attachment eyes held in place by a cotter pin. The cotter pin had been installed prior to the start of the trip out of the hole. It is assumed that the pin was defective and came away; allowing the clevis pin to back out of the chain loops and allowing the tugger hook to fall to the drill floor. The weight of the hook was approximately 7ozs (210gms) and fell from a height of approximately 90 feet (28m).