At least one person was seriously injured when a massive fire tore through a vacant warehouse in Humboldt Park early Friday on the West Side.
Crews responded a little after 4 a.m. to the blaze at Grand and Homan, according to the Chicago Fire Department.
A third alarm was called to bring more firefighters, who were taking a defensive approach to the fire as the roof collapsed, fire officials said.
One person was taken in serious condition to Stroger Hospital, officials said.
Crews were trying to contain the fire as of 5 a.m.