Boulder Fire-Rescue shares fire investigation information for Whittier Apartments Fire.

After a thorough investigation, Boulder Fire-Rescue (BFR) has closed their portion of the investigation into the Whittier Apartments fire, which began on Oct. 19, 2021. BFR has determined the origin to be on the exterior of the building near the west side of the apartment complex. The cause of the fire has been declared undetermined.

From the origin area, the fire spread rapidly on the exterior of the structure. The exterior was typical wood frame with wood exterior siding and other combustible construction components. While there were no fire sprinklers on the exteriors or within the attics of the buildings, the occupied space of all six buildings, as well as the garage, were fully fire sprinklered. From the investigation it was determined that the fire sprinkler system for the interior apartment buildings and garage did operate and function correctly. In addition, there was no known fire or building code violations that would have led to the fire.

Along with investigating the origin of the fire, BFR with assistance from Boulder Police and the Denver Field Division of the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), did a thorough investigation into possible causes. Once the team determined the origin area, multiple investigative techniques were used, including K-9 accelerant detection dogs, comparative analysis of possible ignition sources and extensive lab testing. After reviewing all reports and findings, there were no ignitable liquids found nor any other found sources of ignition. Therefore, the cause of the fire has been declared undetermined, with no found evidence of intentional fire setting.

As a reminder, BFR’s portion of the investigation focuses on cause of the fire and origin of the fire start. Further information surrounding the investigation portion that is being managed by the Boulder Police Department is not yet being released, as the police investigation remains open. Boulder Fire-Rescue’s investigation will remain closed unless additional information is brought forward or discovered. In addition, all recovery and access needs for the property were transferred back to the property management agencies once investigators completed their on-scene assessments.

The City of Boulder once again would like to express their gratitude to all assisting agencies, including the Boulder County Sheriff’s Office, University of Colorado University Police Department, Boulder Rural Fire Rescue, Louisville Fire Protection District, Mountain View Fire Department, Boulder Emergency Squad, Denver Fire and the Denver Field Division of the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF). We extend our deepest condolences to every community member that has been affected by this fire. For any community members with housing support needs, they may find additional support through the City of Boulder’s Eviction Prevention and Rental Assistance Services Program: https://bouldercolorado.gov/services/eviction-prevention-and-rental-assistance-services-program