CHICAGO (STMW) -- A firefighter was injured while working on an extra-alarm fire in the Pilsen neighborhood on the South Side early Tuesday.

The fire at the vacant building in the 1300 block of West Cullerton Street was first reported about 3 a.m. and was upgraded to a two-alarm blaze 20 minutes later, according to Fire Media Affairs spokesman Joe Roccasalva.

Flames were on all floors of the three-story building, Roccasalva said. By 4 a.m. five hoses were being used to douse the blaze.

A firefighter sustained a minor injury, but more details were not immediately released, according to a tweet from Fire Media Media affairs.

The fire was mostly extinguished by 4:15 a.m., but firefighters were chasing remaining "hot spots," including one on the roof, Fire Media Affairs said.

(Source: Sun-Times Media Wire © Chicago Sun-Times 2015. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)