Trek Navigator 200

What happened

The bike had been locked to itself in the vestibule of a friends building where I had been house sitting for three days. I last saw it at 8pm, Thursday, Sept. 11th. I went downstairs at 11:30am this morning (Friday, Sept. 12th) to find that the bike, lock & chain had been stolen. Only my helmet was left behind. This leaves me to believe that it was taken by a neighbor or friend of a neighbor as the thief would have had to bypass 2 security doors to get to my bike, but I have no proof of this. There are 2 other bikes locked to themselves in the exact same area.

Bike details

Type
Cruiser / Comfort Bike
Color
Grey
Size
16 " in
Condition
The bike was nearly new. It had a tune up in the spring & was in excellent condition. 2+ years old with minimal wear & tear. 1 somewhat stripped brake cable.
Serial #
GX924112

Theft circumstances

Date
Sep 12, 2014
Lock type
Other
Locked to
Bike was locked only to itself.
How locked
Bike was locked only to itself, through one or both wheels.
How defeated
Lock is missing, along with the bike.
Duration
3 days
Area
Other situation, please describe below.