For once, Portlanders knew where the sound of a loud explosion originated.
Demolition crews used a series of controlled explosions to bring down the water tower on the former Centennial Mills site Monday afternoon, after an August 2 blaze degraded the building’s stability.
The former flour mill sat vacant for decades along Northwest Naito Parkway in the Pearl District, and is set to be redeveloped into mixed use housing and retail. Before the city could issue a demolition permit, the abandoned industrial structure caught fire, destroying most of the building. The cause of that fire has yet to be determined.
The August 2 blaze left a hollowed out, unstable structure with a water tower atop. Building inspectors and engineers at the city said the multi-story towers were at risk of collapse due to rumbling from nearby freight and passenger trains, posing a major safety risk to people and property nearby. In response, Portland Mayor Keith Wilson declared a public emergency. Streets immediately surrounding the area remain closed off. The city’s permitting and development department made arrangements with the property owner, Stuart Lindquist, to have the structure completely demolished.
“Because the building is at imminent risk of collapse, the work requires specialized engineering, equipment, and demolition expertise to protect workers, adjacent infrastructure, the railroad, and the surrounding community,” a city news release noted. “The condition of the structure also limits the number of contractors with the specialized experience, equipment, and capabilities to safely perform this work.”
Due to the building’s age and the presence of asbestos and lead paint inside, the city has been working with the Oregon Department of Environmental Quality (DEQ), the Environmental Protection Agency, Oregon Health Authority, and Multnomah County Public Health to monitor air quality surrounding the site. According to the city of Portland, prior to Monday’s explosion, air monitoring showed contaminant levels outside the immediate fire area “do not pose a significant health risk to the surrounding community.”
According to the city, the site had “extensive asbestos abatement” work done years ago, but not all of the material was removed. The day of the demolition, the city reiterated it is working with the Oregon DEQ “to ensure proper asbestos abatement protocols are followed and to mitigate airborne hazards, including dust and particulate, as the building is demolished.”
On Monday, the explosion of a water tower that sat on top of the building marked the first phase of demolition. The legs of the water tower were destroyed, causing it to tumble down inside the building, as planned.
“The demolition contractor will now prepare to take down the remaining walls using a high-reach excavator,” Eric Kutch, director of Portland Permitting & Development, explained in a city announcement. “The building remains a collapse hazard, so it is important that people continue to stay away from the site while crews work to complete the demolition safely and efficiently.”
Prior to the scheduled demolition, investigators with Portland Fire & Rescue said they don’t believe anyone died in the August 2 fire. Last week, city officials reported that K9s detected human remains inside the building, though it’s unclear how old the remains might be.
Portland Fire & Rescue is managing the site, and the fire bureau will have a lead investigator embedded with a Portland Permitting & Development work group tasked with planning the future stages of the building’s demolition, a city spokesperson explained.
