They don't really need to get into the bunker. I'm assuming said bunker has limited supplies of food, and that it is reliant on the outside world for water, ele

They don't really need to get into the bunker. I'm assuming said bunker has limited supplies of food, and that it is reliant on the outside world for water, electricity, and network connectivity. Just yank the network and turn off the water, it'll either be pointless to stay inside, or untenable. Either way gets the door open.