The flames broke out on the second floor of the West 188th Street building just before 4:45 a.m.
The fire quickly spread through the upper floors of the six-story building.
Fire marshals determined that a family on the second floor, who only has one outlet in their residence, plugged several large appliances - including a space heater, television and refrigerator - into a power strip, which was fed by an extension cord. The extension cord could not handle that amount of electricity and caught fire, spreading to the bed.
The family was awakened by the smoke alarm and escaped without serious injury.
The building houses about 55 apartments.
One firefighter suffered minor injuries.
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