According to CBS Philadelphia, firefighters were called to the 6500 block of Gesner Street around 2:45 a.m. Saturday. Upon arriving, crews said the fire was spreading.
Five homes were destroyed and another three damaged before crews were able to get the fire under control around 4 a.m.
Firefighters found the four children in one home. Officials say a 4-year-old boy, twin 4-year-old girls and a one-month old boy died in the fire. Two 11-year-old girls were treated at the scene for smoke inhalation.
The Red Cross is assisting the at least 40 people displaced.
Philadelphia Fire Commissioner Derrick Sawyer told CBS Philadelphia the fire marshal is investigating how and where the fire started.
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