A pre-war-underground fallout shelter located in an underground passageway filled with a pile of wrecked cars. The tunnel has mostly collapsed leaving only one entrance accessible.
There are 3 different floors. At the surface of the tunnel you will find a locker and a bunch of wrecked cars, fix the electrical wiring on the wall to open the door. There is a desk and locker that need to be Lockpicked.
Grab the cord at the elevator to reach the second floor. You will find lockers that need to be Lockpick and in the kitchen tables that can be looted.
If you grab the cord at the elevator on the 2nd floor you will reach the last floor. In the last room, you will find lockers on the wall, that's where high tier gears are located. You will need high level of Lockpick skills and perhaps a Expanded Lockpick Set.
The Tunnel is located at Grid 10 : 23 (due NorthEast of San Francisco).