Chicago - One person was injured on Saturday in a fire that sent flames bursting out of windows from a residence on the 50th floor of the John Hancock Center in downtown Chicago, according to the Chicago Fire Department.

The fire broke out on the east side of the 100-story building in mid-afternoon and was quickly extinguished by responding firefighters, according to tweets by the Chicago Fire Department.

The fire began in a bedroom and spread through the rest of the apartment, gutting it, the department said. The cause of the fire, confined to the one apartment, is under investigation.

One person was injured and firefighters were searching upper floors to check on the well-being of residents, the department said. Residents were advised to stay in place. Multiple ambulances responded to the fire.

The fire department posted pictures of the flames coming from the building as smoke obscured views of the upper floors.

The Hancock building, a landmark in Chicago, has condominiums on most of the upper half floors and an observatory popular with tourists for its sweeping views of the city and Lake Michigan.