Abstract: An iron worker was installing a 17-ft vertical column section to a horizontal truss steel section. A crane was used to lift the column into position and held the column in place with a choker. The employee temporarily secured the vertical column to the truss with a small right angle metal erection dip weld at the base of the column. The top end was to be secured by two large bolts on each side of the column. The employee climbed onto the column to remove the choker that held the column in place. The temporary weld failed and he fell 20 ft to the floor below. The employee suffered a broken back and was hospitalized.