As we were ascending the roof of Mercy Hospital, the Tank blocked the elevator doors with some large metal object, and we had to keep mellee-ing it while being assailed by waves of infected. Two of us got through, somehow, but me and the other player were still stuck in the elevator, with no way of getting past the obstacle. Eventually, the two who escaped reached the safe-room, while we were still alive, but nowhere near he saferoom. We looked at each other in the elevator, and realized that, in order for us to make it to the next level, we would have to kill each other, for the greater good. It was a silent understanding, and with that, he shot me until I was incapacitated, then I shot him until he was incapacitated; we then barraged each other with pistols until we expired. It was a emotionally harrowing experience, but not without a silver lining: we all came back to life for the finale.
