WHITING, Ind. (CBS) — A fire that gutted a three-story building in northwest Indiana two months ago likely was the result of arson.

CBS 2’s Susanna Song reports Indiana state fire marshals ruled the Jan. 20 fire at a 117-year-old building at 119th and Sheridan in Whiting, Ind., was caused by ignitable liquid on the floor of the dress shop on the first floor, and have handed over the case to police.

Fire officials knew all along the blaze started in the dress shop on the first floor before it spread upstairs, where there were seven apartments. Tests of floor samples found evidence of an incendiary liquid, and fire marshals suspect it was a case of arson.

Police want to talk to a man considered to be a “person of interest” in the case. They said the man is not cooperating with the investigation, and has fled the area.

Whiting Police Det. Sgt. Brad Stelow said, “during the investigation, different things have come up, and we wanted to speak to him, because he might have been in the area, and that’s about all I can say about it.”

The man police are looking for did not live in the building. Detectives would only say he’s from Illinois.

Stelow said the investigation is ongoing.

Seventeen people lost their homes in the blaze, and Lubia’s Dresses and Events shop was destroyed.

Police were asking witnesses or anyone else with information about the fire to come forward. They said the dress shop owner has been helpful in the investigation.

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