A “significant” blaze torched the seats and sparked an evacuation at the home stadium of NFL team Denver Broncos.
Firefighters were called to Empower Field at Mile High stadium in Denver, Colorado, at around 2pm local time on Thursday to tackle a fire that grew to around 1,000 square feet and sent smoke billowing over the city.
Empower Field at Mile High said in a statement on Twitter that the “small fire” began in a construction zone near the East Club Lounge, causing that area of the stadium to be evacuated “as a precaution”.
No injuries were reported and Denver Fire Department crews managed to contain the fire quickly.
At the time of the blaze an event of around 100 people was taking place on the the second level of the stadium, Fire Department spokesperson Greg Pixley said at a press conference.
The fire was “significant” and 75 firefighters battled to put it out even after the water sprinklers kicked in, he said.
The source of the fire remains unclear, with the investigation still ongoing.
Dramatic images, shared by Denver Fire Department on Twitter, showed the roaring flames and thick black smoke engulfing a seating area of the American football stadium.
“#DenverFireDepartment crews are extinguishing a fire at Mile high stadium, 1701 Bryant,” the department tweeted.
“Unknown cause at this time, but fire affected has affected the suite are and the third level seating area.”
Soon after, the department added in a follow-up tweet: “Fire now under control at Mile high Stadium. Sprinklers attempted to stop the fire, but firefighters were needed to complete extinguishment.
“Heavy fire & smoke was found on our arrival.”
Images of the aftermath showed the plastic seating charred and covered in ash and fire damage on an upper level in the northeast corner of the stadium.