Suspension bridges are among the strongest and longest of bridges. How do they work? The deck is suspended from vertical hangers that are attached to two heavy cables. The cables are pulled over the towers and secured by heavy anchors at each end. Weight pushes down on the deck, but the cables and hangers holding it up transfer the weight to the strong towers, which support the weight of the bridge. This "Fetch!" challenge is to design and construct a suspension bridge. Can you build a bridge out of cardboard that won't collapse under the weight of a pile of books?