THORNTON, Colo. — A grass fire in Thornton on Wednesday choked Interstate 25 with black smoke, triggering evacuations and briefly shutting down the interstate.
Pinnacle High School and nearby businesses were being evacuated due to the fire, burning near W. 84h Avenue and Huron Street amid red flag conditions, as Thornton police officers went door-to-door in neighborhoods to the northeast.
A shelter has been established at Margaret Carpenter Recreation Center, 11151 Colorado Boulevard, where resources and assistance are available for those who need them.
Water World was initially established as a safe area for evacuees. However, authorities are now directing people to the Margaret Carpenter Recreation Center.
Authorities have yet to release the number of people impacted by the evacuation orders.
The Colorado Department of Transportation closed I-25 in both directions between Thornton Parkway and W. 84th Avenue due to drifting smoke over the highway.
However, the interstate reopened around 1:30 p.m. Travelers were advised to expect delays in the area.
It's unknown at this time if any structures are threatened or have been damaged. There have been no reports of injuries.
The size and cause of the blaze is not known.
Most of the Front Range, including the area where the fire is burning, is under a red flag warning for wind and low relative humidity. The warning expires at 6 p.m. Wednesday.
Denver7 began receiving reports of a large plume of black smoke shortly before 11:55 a.m. from one of our reporters near Westminster High School.
Denver7 reached out to a Westminster police spokesperson, who said the smoke wasn't coming from their area, and they directed us to call Thornton PD.
Todd Barnes, with the City of Thornton, told Denver7 over the phone that the large plume of black smoke was the result of a “field on fire.”
Thornton Fire Crews, along with several neighboring departments, on scene at Pinnacle High School for a vegetation fire. The school has been evacuated. I-25 has been closed north and south bound at 84th pic.twitter.com/EJMBurJUQe
— Thornton Fire Dept. (@ThorntonFire) February 25, 2026
This is a developing breaking news story and will be updated.
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