The blaze broke out about 3:00 A.M. in a house on the 1000 block of West Indiana Avenue near Germantown Avenue.
When firefighters arrived they found the dwelling engulfed in flames and they were told a number of people were trapped inside, then part of the building collapsed.
Crews managed to get everyone out safely.
There are no reports of injuries.
It took an hour and a half to gain control of the fire.
Investigators say it looks like the fire started in the rear of the building on the third floor.
They are searching for the cause.