I was outside on a mobile call and I accidentally leaned against the wheel chair accessibility button next to the door on Annex II and I was able to get in by pulling the door to the right(if you stand facing the entry door to Annex II). I checked to see if the door was locked properly and it was. I confirmed this with the Library on duty, Caroline Harnly. We do not have a guard on duty until 4:00 p.m. and I discovered this problem at 2:30 p.m. This is a security problem, I hope the right person will be notified by posting this here or give me some insight on what to do about this kind of problem in the future.