Employees #1 through #3 were supervising the pouring of concrete into a 50-foot-tall steel form for the construction of a 72-inch-diameter column intended to support a 24-inch pipe from a pumping station. All three were tied off to the top of the form.
Suddenly, there was a loud “pop” as the bottom of the form blew out. The force knocked the form off the caisson, which was approximately eight feet above the surface of the lake. Bolts holding the two parts of the form together sheared and the form fell over into the lake, taking all three workers with it.
Employees #1 through #3 died of asphyxia by drowning. Employee #1’s body was recovered within a few hours; the bodies of Employees #2 and #3 were found by divers after the form was lifted up onto a barge.
All of the concrete mix had run out into the lake during and after the accident. The pour had taken about two hours but the concrete mix in the bottom of the form was like soup, suggesting that too much plasticizer had been added at the batch plant.
