Abstract: On March 2, 2006, Employee #1, a well driller, and a crew of an oil/gas well drilling were putting a drill string back into a partially drilled well. The drilling equipment consists of a 23,000 lb. traveling block and an attached 180,000 lb. drill string. As they were placing the equipment back into the partially drilled well, it fell uncontrollably to the drilling floor. Employee #1, who was operating the drilling console and draw works brake system, applied the main brake to control the falling blocks and pipe. Smoke formed from the draw works brake system, and the drill string went down the well, stopping by an elevator. The blocks then hit the floor and fell on Employee #1, killing him. The accident investigation revealed that the uncontrolled descent of the blocks was directly caused by the disengagement of the electric brake, a defective draw works brake system, and inappropriate operation of the draw works. Additionally, the employer had an insufficient inspection program, not utilizing manufacturer's instructions for installation and operation. Further, there was a lack of operator knowledge and experience. The electric brake coupling handle latch became unbolted allowing the auxiliary brake to disengage from the draw works, thus it did not provide any braking to help control the drill string descent. The draw works main brakes overheated leading to the brakes complete failure. The brakes were missing retraction springs that pulled the bands from the flanges during periods of nonuse.