The blaze broke out at about 2:45 on Thursday morning along the 5100 block of North Fifth Street in the Olney section of the city.
Flames ripped through the two first floor stores -- a telecom business and a taco restaurant -- and the apartments on the second floor.
There are no reports of injuries.
The apartments were vacant at the time of the fire.
The fire has caused thousands of dollars in damage.
Investigators are searching for the cause.