Structural Failures
Engineer Says Partially Collapsed Iowa Building Was Brittle, Nonredundant
The investigation into the cause of the failure of the six-story building continues.
Photo courtesy of Iowa Task Force 1
The six-story apartment building that partially collapsed in Davenport, Iowa, May 28 is being held up in part by the pile of debris from the top five floors dropping onto the first, a structural engineer says. Police say two people may still be inside the structure and are feared dead.
The remaining structure could collapse at any time, making it too dangerous for anyone to venture inside, city officials say, even after rescuers discovered another woman alive and helped her from the building more than 24 hours after the initial collapse.
The investigation into the cause of the collapse is continuing. Larry Sandhaas, a structural engineer at Shive-Hattery who the city brought in to assess the building after the collapse, said during a May 30 press conference that his firm is bringing in a laser-scanning drone crew to create a digital 3D model of the building to assist in the investigation.
The building is a mix of 84 residential and commercial units, according to Rich Oswald, the city’s director of development and neighborhood services. Records show it was originally built as a hotel around 1906. Steel beams were supported by the exterior brick bearing walls, Sandhaas said. While state-of-the-art at the time of its construction, the building today is brittle and nonredundant, he added.
“When you lose the brick, you lose the stability of the building,” Sandhaas says. “And the building is in imminent danger of collapse.”
Officials previously said there had been complaints of bricks falling from the building. It had been undergoing exterior brick repairs after the owner, Davenport Hotel LLC, received a permit from the city May 24, records show. The permit notes that 100 linear ft of brick was to be replaced.
It was the second repair on the building’s exterior this year. Records also show the city issued a permit for repairs in February, and that the work passed a final inspection May 1.
Oswald said the owner had commissioned two reports this year from Select Structural, an engineer in Bettendorf, Iowa, and that both times the firm found the building sound for people to remain in while the work was performed. Select Structural did not immediately respond to inquiries.
Demolition Planned
The city has issued a notice to the owner that the building must be demolished. Sandhaas says more pieces of the roof appeared precarious.
“It’s difficult to say how soon" it will collapse, he says.
In a statement, the city said it is working with Rock Island, Ill.-based Valley Construction to develop a demolition plan. Davenport Fire Marshal Jim Morris said there is a significant load on the building’s roof from air conditioning units and other utilities that must be removed for a careful disassembly of the remaining building. They also must find a way to demolish the building without damaging nearby properties, Sandhaas says.
City officials previously said demolition would get underway May 30, but work did not begin due to questions about the whereabouts of five people, including the two that police think may still be inside.
Rescue and Recovery
The woman discovered inside the building May 29 was the ninth survivor recovered from the site. Her escape came hours after Mayor Mike Matson said the operation had switched from rescue to recovery.
The news of another survivor, with five other people still unaccounted for even as officials had said there were no credible reports of anyone missing and that demolition was planned to start in the morning, drew protestors to the site that evening who opposed the plan. Matson said the situation remains “fluid and ever evolving.”
Police Chief Jeff Bladel said search and rescue teams had gone through the building and debris pile with dogs trained to search for live victims and human remains, but there had been no confirmed viable signs of life. Matson said officials were unsure how rescuers had initially missed the woman discovered late May 29.
Sandhaas said the way that five stories of the building dropped onto the first floor and basement reduces the chances of voids where a person could have survived. Further searches of the pile had been called off because of the potential for further collapse, Morris added.
“We are currently evaluating the risk assessment of where we can go back into that building to do this other search,” Morris said. “We’re very sympathetic to the possibility that there’s still two people left inside.”
This article was updated on 5/30/23.
