I have a friend who discovered that her garage door was bent deeply inward at the top. She reported it to the police, who explained that burglars frequently will pry the door inward near the top-center, then reach in and pull the disconnect rope. This then permits the door to be raised. A variation of this is to break out a glass window in the door for the same purpose.
No report was filed with the police, since nothing seemed to be missing. The friend bought a new top section for the garage door and had it installed and asked me if I'd install a new operator to replace the old one that was original to the house.
When I went to do the operator installation, I naturally tested the "weight" of the door to make sure the spring was adjusted properly. What I found was that the door had virtually no lift from the spring at all. The fellow who installed the top panel did his work, he apparently never checked the spring tension. The old operator, a screw drive Genie had plenty of power. After years of faithful service, it finally had weakened the top panel enough that rather than open the door, it merely had jerked the top panel inward. This was made worse by the tendency of the rubber strip at the bottom of the door to stick to the paint of the garage floor.
I retensioned the spring properly and when the new operator was installed, all worked perfectly. Not every instance of a bent-in door is evidence of a burglary. It also points out the need to occasionally disconnect an operator and lift the door manually to verify adequate spring tension.