Cerritos homes cluster tightly around a 1974 median build year, which puts most garages on original or first-generation replacement track and spring hardware from a specific era of extension-spring doors and lighter steel sections. That's a different animal from the 1960s builds common elsewhere in the wider Fullerton service area - the rollers wear differently, the track gauge is lighter, and the spring anchor brackets on these doors are a known weak point after fifty years of cycling. The mild coastal-influenced climate here doesn't rust hardware out the way a harsher climate would, so the failures we see aren't corrosion - they're fatigue. Metal that's flexed tens of thousands of times without ever being checked. With roughly 15,763 households in Cerritos and most of them sharing this same build-year window, the pattern repeats door to door: original hinges, original rollers, and springs well past the age where anyone should trust them without a look.