Bicycle detail

My bike was u-locked to the rack on the third floor of the locked parking garage. I tried to unlock the u-lock last night (12/18) at 8:30 pm but the key got stuck. After trying for 20 minutes I was unable to get the key out. Figuring that my bike was safe since it was still locked with a cable lock between the rack, bike frame, and front wheel, and since the garage is locked to nonresidents, I gave up and intended to call a locksmith to come help. I left, went to bed, went to work the next day (12/19), and when I checked on my bike at 10:00 pm it was missing. My best guess is that a resident happened to see me in the garage attempting to unlock the bike and returned for a closer look at the lock afterward.