The door won't open, or it opens a few inches and stalls. Sometimes you hear a bang from the garage, usually a torsion spring letting go under tension, and the door goes heavy in your hands right after. On extension spring setups, one side sags while the other stays put, so the door runs crooked in the tracks. If the opener is doing the lifting, you'll notice the motor working harder and slower than it used to, or the remote clicks but nothing happens because the opener can't move the weight without spring assist. On a lot of the 1960s and 70s houses across this service area, the spring hardware is original or close to it, so the failure isn't sudden - it's decades of cycles finally catching up. A door that's been getting stiffer over a few weeks is telling you the spring is losing tension before it snaps outright.