The failure that gets a call made is usually one cable snapping while the other side holds, which racks the door sideways in the tracks and can bend a panel or knock a roller out if someone keeps hitting the opener button. On the wider two-car doors common in Robins, a single snapped cable puts a lot more uneven load on the remaining side than it would on a narrower one-car door, so the rack tends to happen faster and more visibly here. If a cable has been fraying slowly, you'll usually see it first - strands sticking out near the drum, or the door sitting slightly crooked when closed. That's the window to get it swapped before it lets go. Once it snaps, the door is stuck, usually in whatever position it was in, and the opener should not be run again until the cable is replaced.