Officials say flames were heaviest at the rear of the Bronco Road home when crews arrived just before 2 a.m. Sunday.
ADAMS COUNTY, Colo. — Fire investigators on Monday combed through a badly damaged home in unincorporated Adams County, a day after a fast-moving blaze killed two people and a dog in the north Denver suburbs. Crews were called at 1:49 a.m. Sunday to the 800 block of Bronco Road, where the back of the house was engulfed.
The fire drew a large response from Adams County Fire Rescue and the Adams County Sheriff’s Office, which is assisting with the investigation. The cause remains undetermined. Authorities have not released the victims’ names pending coroner notifications. Investigators said they are working to establish where the fire began, how it spread into the interior and attic, and whether any mechanical, electrical or human factors played a role. Officials also said it is unknown if smoke alarms were working at the time, a detail that could clarify the occupants’ window to escape.
When firefighters arrived, flames at the back of the structure were already moving through void spaces. Crews attacked the fire from the exterior and advanced inside to cut off extension to the attic. A dog was found dead inside. Two people died in connection with the fire; officials did not immediately release their ages. “The back of the home was fully engulfed when crews arrived,” the department said in an initial summary. Investigators typically examine appliances, exterior outlets, grills or heaters located on patios, as well as wiring and vents, when heavy fire is reported at the rear of a residence.
Deputies kept the block closed to through-traffic while the fire department documented burn patterns and removed debris for closer inspection. The house is west of Interstate 25 and U.S. 36 in a neighborhood of single-family homes. On Monday, crews checked the attic framing and sheathing, looking for directional charring and any signs of a secondary ignition. The sheriff’s office said there was no immediate indication of a broader threat to nearby properties. No firefighter injuries were reported.
The deadly fire follows several recent metro-area structure fires that did not cause fatalities but strained overnight staffing. As colder nights settle in, investigators often see incidents tied to space heaters, fireplaces and outdoor ignition sources near siding or decks. Officials stressed they have not identified a cause in the Bronco Road case and are keeping multiple possibilities open until lab results and full interviews are complete. The coroner’s office will determine the cause and manner of death and confirm identities.
Procedurally, the investigation moves into a documentation phase: photographing and mapping the site, collecting samples if necessary, and reconciling witness timelines with physical evidence. Once complete, findings will be compiled in a report and, if any code or criminal issues arise, forwarded to the appropriate authorities. Authorities said further updates would be released after next-of-kin notifications and preliminary testing.
Neighbors described a quiet street jolted awake by sirens. One resident said they saw “orange light licking over the fence” before engines arrived. Another said crews remained on scene for hours pulling smoldering material from the attic. “It’s devastating,” a neighbor said, watching tape flutter in a light morning breeze.
As of Monday afternoon, officials had not identified the victims or determined a cause. Investigators plan to return to the property this week to continue examinations and coordinate with the coroner on timing for the release of names.
Author note: Last updated November 10, 2025.