The fire started just before 6:30 a.m. along the 1800 block of North 23rd Street in North Philadelphia.
Heavy smoke was pouring from the building when firefighters arrived and they immediately called for more engines.
As firefighters checked the homes for occupants, the view from Chopper 6 showed other firefighters cutting through the roof to reveal orange flames that came billowing out of the openings.
Nobody was injured in the fire, but a number of families were displaced.
It took firefighters about 20 minutes to get the blaze under control.