The service door, which opens to my enclosed backyard, was open. I had been in and out of the garage earlier. today. At 1:58 PM, I was called by my neighbor Anne, who had been contacted by her neighbor Susie (both at 935 W Montana). Susie had seen someone throw a bicycle over the fence toward 939 W Montana. She called 911. Her description is a young black male, "taller than" me, which means over 5' 9". He wore a hoodie and jeans. Other things in the garage were disturbed. I haven't determined if anything else is missing but there is nothing obvious. I don't know how he entered my fenced and gated yard, or knew of the open door. The main garage door was closed.