West Chicago's housing stock centers on 1980, a few years newer than the 1976 median across the wider service area we cover from Wheaton, but the difference isn't as large as it sounds. A door installed in 1980 has still had four decades of Illinois winters to work on it. This region sits in a cold moderate climate band, where freeze-thaw cycling works at bent track hangers all winter until a cold snap finally pulls one loose, usually right when you're trying to leave for work. With 7,436 households in town, that's a lot of doors that went up in the same building boom and are now hitting the same age-related failures at once, worn rollers, loosened track bolts, hinges that have stretched their screw holes. The other common cause is simpler: something got backed into, a bike, a car mirror, a trash can lid caught by wind, enough to knock the bottom section out of alignment even on a door that's otherwise fine.