At 11 a.m., the building collapsed while firefighters were working on some hot spots.
A nearby apartment building was evacuated, but no injuries had been reported.
The cause of the fire is under investigation.
Firefighters were on the scene late Friday morning at a fire that burned through a silk flower shop's warehouse on the Northwest Side.Crews were called to the building in the 4500 block of North Elston in the Albany Park neighborhood at approximately 9:30 a.m., when the fire started.