CHICAGO — Firefighters pulled two people out of the rubble of a Washington Park apartment building that completely collapsed after an explosion Sunday night.

At least two people were hurt when the building in the 5800 block of South Calumet Avenue collapsed about 7 p.m., said Larry Langford, a Chicago Fire Department spokesman.

One person was rescued in the rubble about 7:20 p.m., and a second person was pulled out about 7:45, fire officials said. The first victim was taken to University of Chicago Hospital in serious condition.

Chicago Fire scanners just after the building collapsed:

Officials "don’t know what caused the building to explode, but it did," Langford said, calling it a "violent collapse."

Crews are working to determine if there are more victims, he said.

Emergency. Apt building collapse. Building completely down 58 and calumet. Media rolling. — Chicago Fire Media (@CFDMedia) November 24, 2014

Victims trapped in rubble. Search and rescue in progress — Chicago Fire Media (@CFDMedia) November 24, 2014

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