Zombie Apocalypse.

Your judgement was good-intentioned, but it caused many of your teammates to fall. By the time you could clearly see the figures in the dark, they had you ambushed. Zombies rip through your team, and kill off the majority. Your remaining party wholly understands your decision to wait until you could see the figures, but now they're weak. You kill the rest of the hostiles, now it's time to rest and recuperate.