Jurupa Valley's median home dates to 1980, which puts it near the older edge of the service area's 1938-2007 build span - earlier than a lot of the 1980s-and-90s tract stock that fills out the other communities we cover. That matters because a door installed around 1980 has had over four decades to work its rollers loose, stretch its cables, and let its track brackets creep out of alignment a fraction of an inch at a time. None of that shows up as a sudden failure - it shows up as a door that finally jumps the track on an ordinary Tuesday.
The region sits in a moderate heat climate band, and that kind of steady warm-and-dry cycle dries out old nylon rollers and stiffens the grease in track hardware that hasn't been serviced in years. On a door this old, an off-track roller is often the end of a slow decline, not a one-time accident - worn wheel, loose bracket, track pulling away from the jamb, door finally walks off the rail. We do see doors that came off from a single hard hit, but on housing stock this age, the wear story is the more common one.