Firefighters got the blaze under control about 8:15 p.m., but continued to work hot spots, said Natalie Ridderbos, a Brighton Fire Rescue spokeswoman.
Homes nearby the fire, which is on North Main Street near Longs Peak Street, were evacuated. North Main Street was closed north of East Bridge Street, she said. Firefighters urged people to avoid the area.
One person was initially stuck inside but was able to get out before firefighters arrived, Ridderbos said. There were no reports of injuries.
Crews were on-scene at about 3:45 p.m. Brighton firefighters were helped by neighboring fire departments including South Adams, Fort Lupton, Hudson and North Metro.
The building, which is a total loss, included an auto body shop, a market and hair salon.
Multiple flammable materials inside caused several explosions, so crews were unable to enter and worked the fire from the exterior.
The fire likely began in the auto body shop, the fire district said. The cause of the fire remains under investigation.
Thank you to The Denver Post for reprint permission.