Memorial Bridge is the third chapter in the customised Cold Stream campaign which was subsequently beta-released as a DLC in March 2011. The Survivors leave the safe room and climb a series of stairs, dealing with a small handful of passive Common Infected found along the way. A ladder leads up to the open air, and gives access to the roof of a concrete service structure, located in a small park next to the Memorial Bridge. The park is densely populated with Common Infected who will respond aggressively to the sight of the Survivors. A Tank can also sometimes spawn in this area. In any event, the fighting is intense, but not too difficult if the team stays up on the structure and allows enemies to follow their scripted attack lines to climb its walls, bringing them into close range vulnera