UPDATED: 10/21/10 10:03 a.m.

OAK PARK, Ill. (CBS) – A late-night fire in Oak Park caused at least half a million dollars in damage.

Emergency officials responded shortly after 10 p.m. Wednesday to the fire at 440 S. Kenilworth Ave. and found a blaze on the rear porch of a 3 1/2 story brick apartment building, Oak Park Fire Dept. Deputy Chief Kenneth Klemm said.

The fire reached all the way up the rear of the six-unit building — which was being remodeled at the time — and caused extensive damage to the rear of each unit, Klemm said. The back porch was destroyed and the apartments were uninhabitable following the blaze.

Three people who lived at the building, including a couple and an older man, escaped without injury and no one was hurt responding to the blaze, Klemm said. Crews took less than an hour to extinguish the fire.

Officials initially estimate that the building sustained at least $500,000 or more n damage, Klemm said. Previous reports listed the address of the fire as 848 W. Madison St., about a block away.

The cause of the fire had not been determined and was under investigation Thursday morning, Klemm said.

The Sun-Times Media Wire contributed to this report.

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