Explosion at Sandman Hotel raises questions about building’s structural integrity

One of the lingering questions about this week’s explosion at a historic Fort Worth building is the structural integrity of the century-old structure.

Fort Worth, state and federal officials are all investigating what caused the explosion in the Sandman Signature Hotel at the base of the 20-story W.T. Waggoner Building and whether it can be repaired.

Experts not involved in the investigation said the explosion, which damaged the building’s sub-basement, basement and first floor, raises questions about the structure’s ability to bear the weight of the floors above.

“The most critical structural component are the columns in the first floor, because they carry the heaviest load,” said Simon Chao, a professor at the University of Texas at Arlington’s civil engineering department. “If the columns were overly damaged, not only on the first floor but even the upper floors, it could cause the collapse of the entire building.”

Structural experts from the Federal Emergency Management Agency examined the building Monday night but have not said anything publicly about their determination of the damage.

The building’s structure is made of a riveted steel frame with reinforced concrete. Investigators are likely looking at the most important elements to determine if the structural integrity has been compromised, Chao said.

“With components made of steel, they’re looking to see if there’s a large deformation or warping, which could lead to buckling,” he said. “For the concrete system, the most direct sign is if there’s a crack.”

Assessing the damage isn’t as simple as a visual test, said Norman Alston, founder and principal of Dallas-based Norman Alston Architects.

“They’re looking for visual clues to suggest what else may have happened,” he said. “It’s hard to delineate since you’re looking for things that aren’t there. A lot of this is a feel, too. Once you understand how buildings go together, you understand where the most present dangers are.”

But both experts also said worries about the building’s structural integrity may be overblown.

“So far, from all the photos I’ve seen, I cannot see any damage to the columns or beams,” Chao said. “I don’t know what’s happened inside, but I don’t feel there’s any concern regarding structural integrity.”

The explosion injured 21 people and shut down downtown Fort Worth’s 7th Street, 9th Street and Houston Street. It’s already led to a lawsuit against natural gas company Atmos Energy and the companies that own or manage Sandman Signature. Northland Properties, Canada’s largest privately owned hospitality company that’s headed by Dallas Stars owner Tom Gaglardi, opened the hotel in March 2023.

The building was constructed for William Thomas Waggoner in 1919 and opened in 1920. Waggoner was a rancher, oilman, banker, horsebreeder and a philanthropist.

Back then, engineers and architects didn’t have access to advanced technology or materials and often over-engineered buildings to ensure their safety, Alston said. Before it opened, the building was touted as a model in “durability of construction,” according to a 1919 Fort Worth Star-Telegram article.

That means the building’s age could have potentially saved lives, Alston said.

“There is something of a Darwinian aspect to historic buildings. A building that has survived for 100 years or more is an indication that it had something going for it when it was built,” Alston said. “It suggests a level of care and quality that allowed it to still be with us when most of its contemporaries have been lost.”

Alston, whose firm works on historical renovations, said it could take a while to put a dollar figure on any needed repairs.

“If a bomb went off in your car, you’re not taking it to a mechanic to get an estimate, right? It’s going to take some time to assess the scope of this,” he said.

The building’s placement on the National Register of Historic Places also isn’t expected to slow repairs, said Natalie Foster, communications specialist for the City of Fort Worth.

“There isn’t a special process to carry out repairs, neither through our organization nor in coordination with the state,” she said. “Because of the importance of this historic property, if the owner wants to remodel, our city’s development staff is prepared to assist in facilitating the design and providing guidance on best practices for the preservation of the building.”

The building’s historic designation could even open up tax credits to assist in repairs.

“It’s an extremely powerful financial tool that could provide fairly substantial financial assistance for a project like this,” Alston said. “It’s almost always more cost-effective to repair and restore than to replace it. I believe in saving buildings like this when you can.”