Abstract: At approximately 10:30 a.m. on March 19, 2007, Employee #1, an ironworker, was connecting structural steel during construction of a medical center. He had been working at the site for three weeks. He was standing on the top flange of an 18-inch I-beam, 31 feet 7 inches above a concrete surface, waiting for another I-beam to be delivered to his location by a crane. The proper I-beam could not be immediately located and he began walking east on an I-beam, and turned north on another I-beam. There were conflicting statements about whether he was walking on the top flange of the I-beam, or walking on the bottom flange of the I-beam (cooning). Physical evidence and credible statements indicated that he was walking on the top flange of the I-beam. He stopped to adjust his tool belt and his foot slipped. As he began to fall, he dove forward and attempted to grab the top flange of the I-beam he had been walking on. He was not able to maintain his grip, fell, and struck another structural I-beam that was 11 feet 7 inches below the beam he had been walking on. He attempted to grab the top flange of this I-beam but was unable to maintain his grip. He fell the remaining 20 feet to the concrete below. He was transported to USC Medical Center, where he was rushed into emergency surgery, stabilized, and was hospitalized for four days for further treatment. He sustained a fractured L-5 vertebra in his back and a ruptured spleen, resulting in internal bleeding. The injured employee was working with, and in close proximity to, another ironworker. The supervisor of Employee #1 had been monitoring the I-beam lifts, and was trying to locate the next I-beam to be connected. Interviews were conducted with the supervisor, the ironworker assisting Employee #1, the crane operator, and the independent building inspector. The investigation concluded that Employee #1 had been walking on the top flange of an I-beam, 31 feet 7 inches above a concrete working surface, without fall protection, as required.