Later on in the game the twilight monsters take the bridge through their portal. Once you are able to go into the desert, go there. Then go where the owl statue is ( once landed from the canon, keep going forward.) Keep going until you see a thing than looks like a building. Clawshot the flying plant and land on the ground that is elevated. A portal will appear and the monsters will come down. Kill them and go closer the bridge (thing that looks like a bridge). Minda will say "what should we do?" say warp and warp to where tha broken bridge is. Now it should be fixed.