CHICAGO (CBS) — Firefighters battled an extra-alarm blaze early Wednesday that spread to two vacant buildings in the Back of the Yards neighborhood on the South Side.

Firefighters responded shortly after 3:30 a.m. to the fire in a two-and-a-half-story building in the 5300 block of South Laflin, according to Chicago Fire Department Cmdr. Walter Schroeder.

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The blaze spread to a neighboring vacant building and was upgraded to a 2-11 at 3:49 a.m., he said. The fire was struck out at 4:15 a.m. and no injuries were reported.

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The building in which the fire originated was “unstable” after the blaze and the city’s Department of Buildings was called to the scene, Schroeder said. The cause was under investigation.

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