CHICAGO (AP) — Firefighters in Chicago are still battling a massive warehouse fire on the city's South Side that officials say is one of the largest fires in recent years.

First Deputy Fire Commissioner Charles Stewart III says frigid temperatures made the fire more difficult to handle. Stewart says the Chicago Transit Authority brought in warming buses so that firefighters could seek relief from the cold. City crews also are working to salt the roads around the building to help deal with a build-up of ice.

More than 170 firefighters responded to the five-alarm blaze at about 9 p.m. Tuesday, and firefighters were still working to extinguish the fire Wednesday morning.