The Destroyed Bridge is an unlockable location on the map. To unlock it, you'll need:
150 Wood
75 Nails
50 Rope
450 Scrap Metal
25 Iron Ingot
1 Bridge Blueprint
75 Wire
50 Bolts
45 Wooden Plank
5 Tool Box
There is a Military base past the Bridge, but you must build the Bridge first. No one has managed to repair the bridge yet. More information will be added once players progress to that area.
The game claims Tool Kits are found in Hardware Store (QZ), but none have been found yet.