Main Story - Escape

Go outside and follow the path down south to the marker. On you way, you will enter a radio conversation with someone. During this scene, the closed area beside you with fence is one of the areas you've searched before. Jump up the fence and ride the vehicle by pressing Y at the right door. Keep driving south following the road until you reach the destroyed bridge. Go on foot and walk down the leftside stairs down to the river. There are many zombies here so once you've cleared a group, keep running and don't stop. Down at the river, you need to head across to the other side of the riverbank and climb up on the rightside area stairs.