With roughly 1,172 households in Lomira and a housing stock centered on 1991, the doors we see here tend to run steel roller doors on lighter-gauge track than the older one-piece doors common in the pre-1970 stock elsewhere in the county. That lighter track holds up fine under normal use but flexes more if a car bumper or a stray basketball catches the bottom section, and repeated flexing eventually walks a roller out of the channel.
Cold is the other factor. We're in a severe cold climate band here, and metal track contracts in deep cold the same way any metal does - a bracket that's slightly loose in July can be the thing that finally lets go in January when everything's stiffer and less forgiving. It's not usually one big event that knocks a door off track; it's a small weakness that finally gives out on a cold morning.