The area runs a cold-moderate climate band, which means real temperature swings through the year rather than steady heat or steady cold. Steel torsion springs lose a little tension and flex differently as metal contracts in cold snaps and expands in summer heat, and that cycling is part of what wears a spring down over its lifespan. A spring installed in 2004 has been through roughly twenty of those seasonal swings, on top of daily door cycles from a household.
Locust Grove's median household income runs noticeably higher than the broader service area's $50,060 figure, and homes here tend to carry larger, heavier doors - double-wide insulated sectional doors rather than the lighter single doors common on older stock. A heavier door puts more load on the same two springs, so when one goes, the other is usually close behind even if it hasn't snapped yet. We check both every time, not just the one that broke.