Bike was locked to wall (hanging) bike rack inside of the Skokie Swift Dempster terminal, 10 feet from the glass-walled attendant's booth. Attendant is on duty at all times, but roves about the termina.l I used a heavy combination Kryptonite cable lock, weaving it through both wheels, the frame, and the wall mount loop, as well as through my Bell helmet. As always, I carefully checked that the cable had indeed passed through correctly and that the combination was scrambled--I was in no sort of rush that day. This was at about 8:15am. When I returned at around 8:30pm, bike, lock, and helmet were gone. No debris was to be found below the rack. A search of nearby garbage bins turned up no traces of lock or helmet, or pieces thereof. I called Skokie PD immediately and officer Klamer (Star #247) took the report and issued me an incident referral card. Security attendant (not a CTA employee) claimed he had not seen or heard anything since he had begun his shift a few hours previously. The next day I quizzed the CTA afternoon attendant, who noted that, although she had had several distractions, including an elderly client falling down in a turnstile and requiring medical help and a fire in a planter pot outside, she had noticed no odd sounds or actions, and seen no suspicious activity around the bike racks. The following day I asked the morning attendant, who also claimed to have seen nothing. There are no video cameras in the Swift Dempster terminal--the only station in the CTA train system where that is true, I am told.