Because nobody could warn them against it, the Roamers have decided to see how effectively they can bring down an old skyscraper... after making sure nobody is squatting inside.
"I've got some explosives in the boat."
"I'm really hoping you haven't been there yet."
"Nah. That'd be rude. Plus it's still being all floaty, too much of a pain."
"So you can't fly, interesting."
"I could get up there if I wanted to. It's just that it'd be too much of a pain."
Shrug. "So, explodey things?"
She leads him to the boat. Or more specifically, the converted shipping pallet she uses to ferry people up and down from it. "Going up!"