Permanent Support Missing

No permanent supporting elements had been put in place before the incident.

"It was determined that the East wall had been braced with 3 wooden braces on the inside of the wall and 3 wooden braces on the outside of the wall since it was built approximately 2 weeks before the accident," the report says. "It appeared that the 3 inside braces were in place on the East wall when it fell."

Two-in.-thick, 10-in.-wide and 16-ft-long scaffolding board braces were aligned in parallel on each side of the wall, at each end and in the middle. The vertical boards had a 2x4 board as a cleat, placed horizontally at 9.5 to 10 ft, to hold a 16-ft board wedged at an angle between the cleat and a 4-ft piece of rebar driven into the ground. Two masonry blocks rested atop the rebar and the board holding the system in place.

Employees interviewed on-site told the investigator that an individual, whose name was redacted in the report, came to the site the day before the incident and saw that braces were covering some of the control joints that needed to be caulked.

The individual went to the job trailer to ask that the braces be relocated and, later that day, "noticed that the braces that were blocking the control joints had been taken down and not put up in a new location," the report says. The report does not indicate if the braces at issue were on the west wall or the east wall, which collapsed.

However, it does say that employees said they were told to move braces on the west wall, which was being waterproofed. The crew removed—instead of shifted—seven or eight braces off the control joints, the report notes.

"The employees stated that they did not remove any of the braces from the East wall," the report says.

Forensic Evidence

But the construction health and safety officer who arrived at the site about two hours after the incident "observed a set of [bracing] boards on the ground under the wall … running parallel to the wall" but they were intact and at each end of the east wall. Those boards and their position "were consistent" with the placement of other bracing boards that were removed to allow access to control joints, it says.