Another commercial building roof collapses in Anchorage

Another commercial warehouse building collapsed in Anchorage on Monday under the weight of heavy snow load, following a season of record-breaking snowfalls.

The collapse occurred before 11 a.m. at a flat-roofed, 17,500-square-foot building at 7920 Schoon Street in South Anchorage.

Ace Delivery and Moving is located at the address, state records show. The building was built in 1982, according to city records

No one was hurt, said Alex Boyd, assistant fire chief with the Anchorage Fire Department.

Anchorage resident Lisa Switzer on Monday evening shared a security video of the collapse taken from a neighboring building on social media. “Oh my God,” a person says as the building buckles.

“The incident was handled with two units who arrived on scene together and completed an evaluation of the structure,” the department said in a statement emailed by Lexi Qass’uq Trainer, public information officer with the department. “Portions of the structure were occupied at the time of the collapse but no injuries were reported.”

Municipal inspectors and structural engineers have confirmed that the building contained the same problematic wooden roof trusses that have led to other collapses, including those following heavy snowfall last winter, Boyd said.

The incident marks at least the third time this winter that the roof of a commercial building in Anchorage has failed. In late December, a huge portion of the roof at Spenard Builders Supply’s dispatch center was destroyed, followed by the partial collapse of the roof of a vacant, condemned warehouse in Midtown.

In November, local officials issued guidance to commercial building owners to keep roofs clear of accumulation in order to avoid risking catastrophic damage.

“Wind loading and ice damming can cause these loads to be heavier so each roof should be evaluated individually for its specific condition and load,” the fire department statement said. “A structural engineer is the best person to conduct a building evaluation and determine risk and or safety.”

The problematic roof frame in Monday’s collapse and several others on commercial building roofs consist of wooden, parallel-chord roof trusses. Metal gang plates that help hold the wooden beams together were often inadequately placed or undersized.

Buildings built before 1990 have in several cases been found to have the trusses, Boyd said.

“They are not performing to code standard as designed,” he said. “We’re seeing collapses in the 20-25 pounds (of snow) per square foot, which is right where we’re at now.”

Anchorage code typically requires that buildings support a minimum of 40 pounds per square foot.

Last winter, at least 16 buildings in the municipality collapsed, which building officials attributed to the heavy snow loads exacerbating decades-old design flaws.

Boyd said that several roofs in the area around Schoon and neighboring King Street appear to have a similar construction vintage and style, prompting city officials to evaluate other buildings in the area on Monday.

Jerrod Vaughn, co-owner of the warehouse building just to the north of the collapsed building, said he was in the office of his HVAC supply company when he heard the neighboring roof collapse, sometime around 10:40 a.m. or so.

It sounded like a freight train, he said.

“I thought it was an earthquake at first, but it was definitely not an earthquake,” he said.

He checked on his employees, and employees of the collapsed building who had gathered outside, he said. Everyone was safe.

“The moral of the story is people to need to shovel flat roofs in Anchorage,” he said. “The storm (on Sunday) might have just added enough weight.”

Vaughn said his business shares a wall with with Ace Delivery and Moving. He said his unit is being evaluated to make sure it’s safe.

More than 7 feet of snow has fallen this winter in Anchorage, far exceeding the average snowfall with months of cold weather to go.