stolen 1990 Trek 950

I left my bike parked outside of my office at 2pm, locked (or so I thought?). I have been a bike owner in the city for 9 months so I am pretty sure I locked it correctly. However, when I returned at 6pm, the bike was gone and the lock was on the ground. I literally bought it less than 24 hours ago, pretty heartbroken. Please keep an eye out for it.