I feel like a lot would live in disbelief until it got too close to the end. Some would still stay loyal to their bosses until the end. And yeah a bunch would travel.

I think something that devastating would be scary, IRL, because hitting the earth with that amount of force would probably have a shockwave at near the speed of sound if not more. That means most would never heard it coming until they're already floating or hurdling away from what was the ground...