Bunker Zulu is a not yet added Bunker in last day on earth. The CAC card Zulu can be found on the dead body of The Big One, however killing him is near impossible due to his 1000 hp, near instant kills, 128 speed, and his near 100% armor. For now it is recommended to focus on the reachable Bunker Alfa, and Bunker Bravo, as these can actually yield rewards (though Bunker Bravo's lobby and other floors can not yet be accessed due to the computer that is supposed to be hooked up to the entrance not being there.