Turns out you just sort of shuffle and die
Remember that crazy Battlefield 4 E3 demo where the skyscraper came tumbling down and "leveloution" became a word? Yeah, that was great -- the collapsing building, not the buzzwords.
But have you wondered what it looks like to be in the building while it come down? YouTuber TerryxMasters did, and apparently the answer is that you just shuffle around some and die. I was hoping for some hamster-in-a-wheel tumbling, but I suppose that would be too tasking. If by some digital black magic that would be possible, oh please DICE, hear my prayers.