Bicycle detail

I live on the 4th floor of the U apartment, and I parked my bike, along with my U-lock and cable, on my apartment's balcony. I left home on August 30, and the bike was still there when I left. All of my roommates moved out on August 31, and they confirmed that the bike was still there when they left. Nobody was at home around the unit for 15 days, so I suspect that someone who has access to the unit stole it, probably someone from the apartment management team or maintenance. Also, I would like to add that from September 1 to 15, only the apartment had access to our unit as all of my roommates moved out, and I was abroad.