Dr. Pilette was retained to determine the cause of the structural collapse. Concrete has been poured around that base of the affected column hours after the collapse, and effectively entombed the physical evidence needed to determine the factors that led to the building collapse.
As a first phase, Dr. Pilette and his team surveyed the damaged reinforced concrete building to determine the extent of structural damages. The concrete and reinforcing steel were tested to determine their structural properties. A structural analysis of the building was completed to predict the behaviour of the building under several hypothetical scenarios. Dr. Pilette determined that a failure of the column by crushing, thereby resulting in a downward displacement of the column, was the only plausible scenario explaining the observed damages. Others speculated that deficiencies in the building may have contributed to the collapse.
The portion of the collapsed warehouse was eventually demolished under the supervision of Dr. Pilette to recover the physical evidence necessary to complete the investigation. The poured concrete at the base of the affected column was slowly chipped away to uncover the evidence. It was then discovered that the bottom 2 feet of the concrete column was completely pulverized, and that the reinforcing steel was mostly deteriorated due to corrosion. The column had indeed crushed during the repair work. The deteriorated concrete at the base of the column had been chipped away by a construction worker without the installation of shoring to support the roof structure.
