East Harlem fire that burned through Schomburg Plaza apartment building was electrical

EAST HARLEM, N.Y. (WABC) -- Investigators say an overnight fire in East Harlem was accidental, starting in a hard-wired electric heater and then spreading.

The three-alarm fire burned through the 17th floor of a high-rise apartment building.

Nine people, including two firefighters, were injured.

Flames shot out the 17th floor windows of the Schomburg Plaza in the 1200 block of Fifth Avenue just after 11:50 p.m., then climbed to the 18th floor.

Firefighters were flooded with calls from residents saying they were trapped inside their apartments of the 34-story building. They were told to stay in their apartments.

The American Red Cross is in the process of accessing damage.

The fire forced the closure of Fifth Avenue from East 112th Street to East 108th Street to vehicular traffic.