Boulder Fire-Rescue (BFR) tweeted Tuesday morning that they are working a large apartment fire in the 2300 block of Pearl Street.
BFR said that multiple agencies are helping put out the fire that has affected 83 units in three buildings of the apartment complex.
Two minor injuries were reported, BFR said, but those injuries did not require either person to be hospitalized.
Fire crews said they were able to knock down most of the fire since they first called to the scene shortly after 3:30 a.m.
Video from SKY9 showed heavy smoke in the surrounding area. BFR said the fire was considered under control at about 5:40 a.m.
The Red Cross is working to help residents affected by the fire.
Fire crews are asking people to avoid the area as they work to knock out hot spots from the fire.