On 06/27/2022, at approximately 9:30 a.m. four employees were placing a hangar door into place in the opening of the existing hangar structure using a crane and a forklift. The door is assembled on site and placed in the opening of the structure, lying flat on the interior side of the door with the exterior side facing up. The door is placed approximately half-way into the opening. Once at the required height, two welders (one at each end of the door) will weld steel angle iron clips to the existing hangar support columns just below the pivot shoes on the ends of the door. After the door was rigged, hoisted, and lifted into place, welds were partially installed. The crane operator then began to cable down, lowering the exterior bottom edge of the door. The tack welds on the side of the door failed and the door fell to the ground landing on the injured employee.