The door looks tilted in the opening, one corner lower than the other, or it's stopped dead halfway up with the opener still humming. Sometimes a roller has popped clean out of the track and the bottom panel is resting against the frame instead of running inside the rail. Other times the whole track has pulled away from the wall bracket, usually on the side where the spring system puts the most load.
On houses in Alcoa built around 1976 - which covers a lot of the area, per the housing-stock pattern across this whole service territory - the tracks are often original or close to it. Forty-plus years of steel sitting in a garage, through freeze-thaw winters, means the mounting brackets have usually loosened at least once, even if nobody noticed. A door that's been riding slightly misaligned for years finally lets go, and it looks sudden even though it wasn't.