It's a drab afternoon on the grey streets of Chicago as two fire trucks race towards a scene. The mood inside the trucks is determined but light, and the crew jokingly jabs at one another as the driver speeds on down the road. Once on the scene, they learn that a victim is still stuck inside the attic. Lieutenant Kelly Severide, head of the rescue squad, heads in first. He's confident, fearless even. Lieutenant Matthew Casey climbs up the ladder alongside Andy Darden, who breaks in a window before he's given instruction to do so. Realizing the conditions are still unstable, Casey yells at Darden to stay out but Darden's already in through the window. Downstairs, Severide realizes that there's no vent. Thick black smoke begins to get sucked upstairs; an explosion in waiting. Severide hollers for everyone to get down but it's too late. Trapped, Darden perishes, engulfed in flames as Casey watches helplessly from the ladder.