Firefighters spent nearly three hours battling an extra-alarm fire that started Thursday morning at a warehouse in the Back of the Yards neighborhood. The fire started at a warehouse at the Evans Food Group processing plant near 41st and Halsted around 8:30 a.m. Chicago Fire Department officials said the fire was later raised to a 3-11 alarm, bringing in extra crews to fight the flames. Heavy flames and thick black smoke could be seen coming from the roof of the warehouse. District Chief Jim McDonough said the fire spread from the original warehouse where it started to at least two connected buildings. The roofs of all three buildings collapsed during the fire. Crews used three tower ladder trucks and five large hand lines to contain the fire from the outside before it was safe to go inside to extinguish the remaining flames.