Firefighters responded to a 14-story apartment building on 228th Street in the Marble Hill section just after 8:15 a.m.
The FDNY determined that the fire was located in an apartment on the seventh floor.
The 9-year-old was found inside the apartment.
The child received burns and suffered smoke inhalation and was taken to Jacobi Medical Center in critical condition.
A total of 20 units including 78 firefighters from the FDNY responded.
They brought the flames under control just before 9 a.m.
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