Abstract: Employee #1 and two coworkers were assigned the task of increasing the distance between the tops of 44 ft form columns. Employee #1 and one coworker were working from platforms on the columns while the other employee jacked the east side form to spread the top. The platform that had been bolted to the top of the columns served two functions: it provided a working surface when pouring the forms, and it held the forms a specified distance apart. Employee #1 and a coworker unbolted the platform from the west side column and measured the opening as the third worker operated the jack and used a wedge. As he raised the inside of the east column, the platform slid across the top of the west column. The columns had been separated approximately 5 of the required 6 inches when the irregular bottom of the platform apparently became hung up on the column top. Continued jacking caused the platform to jump off the west column. Employee #1 fell with the platform; his abdomen struck a moored vessel and he was killed.