1) Base never collapsed.
2)Worst we got, was 4 Boomers (that'S how we call them - fitting how they always rage and explode for the tiniest of reasons... XD) that literrally got caught by bad aim / junk turrets while we normally either snipe them or M60 their asses to oblivion. So obviously, they all decided to blow up - one after the other... in the same spot. They dug a 10 block deep by 7 blocks wide hole and made a 3x4 hole on the side of the POI we use / repurposed for Horde nights.
I'll add number 3) -> What did you, or do you do to avoid from this situation from happening again?
3) What to do to avoid it - There's someone dedicated to spotting Boomers in our group If possible, they trigger them long range, but close range, they attempt to snipe or AK47 their legs - once downed, they let loose with M60 on their backs. That's the strat and has worked nearly flawlessly since. We're on Day 79 now and only suffered one major blowout from Boomers, the others were controlled to the outside of our perimeter or in the spike fields, away from the main base.