Excerpts from nbcchicago.com:

Two Chicago police officers were among three people injured around 9:15 p.m Monday at a fire in the 3800 block of North Fremont Street in the city’s Lake View neighborhood. Firefighters were able to fairly quickly extinguish the fire on the third floor of a five-story building.

Two male Chicago police officers were injured in the blaze. One suffered smoke inhalation and was taken to Illinois Masonic Medical Center, while the other was transferred Stroger Hospital’s burn unit.  A police escort accompanied an ambulance that transferred the second officer overnight, and a large police presence remained at Stroger as officers awaited word on one of their own.

The conditions of both officers were stabilized. A third victim, a 34-year-old female occupant of the apartment, was also taken to Illinois Masonic for smoke inhalation and was listed in good condition. 

The cause of the fire remains under investigation.