Abstract: At approximately 9:45 a.m. on June 1, 2007, a fifteen-man crew was placing concrete in the two northeast most bays on the third level deck, with thirteen of the crew positioned intermittently along a temporary walkway, extending outward from the third level deck on the north, east and south sides, as the pump operator finished placing the remaining concrete. Employee #4 was checking for water leaks in the formwork from the second deck area directly below the two northeast bays, where the concrete had just been placed. The two northeast most bays simultaneously collapsed, resulting in: Employee #1 and #2 falling down to the ground level; Employees #3 and the remaining crew members bracing onto the third deck as it descended to the second deck; and Employee #4 caught between the second and third decks. With the assistance of emergency rescue crews and other onsite employees, nine employees were transported and admitted to North Memorial Hospital for further assessment. No fatalities resulted from the collapse.