Fire investigators: 5-alarm blaze caused by open flame

Chicago Fire Dept. investigators have determined an open flame started the extra-alarm fire gutted a vacant warehouse Tuesday night on the South Side and continued to burn the rest of the week.

Police are now investigating whether or not that blaze was intentionally set.

Fire Media Affairs spokesman Larry Langford said Friday evening the five-alarm fire was caused by "open flame ignition of available combustibles."

Investigators determined the building had no electrical or gas service, and nothing that would generate a spark to ignite the fire, Langford said. After talking with witnesses and eliminating all other possibilities, investigators made their determination.

The investigation was turned over to Chicago Police, who will decide if the blaze was intentionally set or accidental.

More than 170 firefighters battled the blaze at the vacant warehouse in single-degree temperatures Tuesday night. After the fire was extinguished, Fire Department officials estimated the building had been coated with 6 to 8 inches of ice from the firefighting efforts.

The roof and three walls of the 200-foot by 200-foot structure collapsed as crews fought the flames.

Fire Media Affairs said demolition of the building in the 3700 block of South Ashland Avenue began Friday morning, though fires continued to burn inside.