'It Was Crazy': Witnesses Describe Flames, Smoke Rising From Empower Field At Mile High

DENVER (CBS4)- It's a sight you wouldn't expect to see at Empower Field at Mile High Stadium.

"We were standing outside and we noticed one chair on fire and it started to spread," said Richard Steffens, a witness who was on a tour when the fire started. He and several others were evacuated as the flames spread.

More than 100 seats and a suite area caught fire on Thursday. Within minutes, the fire quickly moved throughout a section of the stadium.

"And right after that you could hear the windows popping out of the glasses, the heat was rising up on the windows in the box seats," said Ross Jones, another witness.

The large plume of smoke caught the attention of witnesses from miles away. Ethan Dunlop was driving on I-25 when he saw the smoke.

"I was panicking a little bit, because I was like 'What's on fire?'" Dunlop said. "A lot of adrenaline, it was crazy."

Along with a tour, employees were also inside the facility when the fire started, but Denver Fire Department spokesperson Greg Pixley said thankfully there were no injuries.

"That caused a pretty good amount of damage within the stadium itself," Pixley said.

About 75 firefighters and 45 fire units responded to the scene. The cause of the fire is still under investigation, but in a tweet Empower Field said the fire started in a construction zone. Pixley said the materials in the seats are what caused it to spread.

"These types of seats involve synthetics and petroleum products when they are created," said Pixley. "And when they burn, they burn at significant rates of speed and temperature and they create that dark black smoke that you saw."

This fire now has those like Dunlop worried about the next time they step foot in the stadium.

"It's very concerning, never know what will happen," he said.