Excerpts from the patch.com:
A fire was reported at 4:02 p.m. Sunday at 69 North Chicago St. in Joliet. When firefighters arrived, flames were coming from the third floor of the vacant building, and there was also fire on the second floor.
Access to the third floor was closed off, so firefighters had to cut through the second floor ceiling. The roof was ventilated and both floors were checked for extension.
Joliet firefighters were on the fire scene for at about 90 minutes. The cause of the remains unknown.
thanks Martin