[It's not a high enough drop to bother tumbling so he just sticks a three-point landing. It only takes a moment to get back on his feet. Underground...got it. Basements and sewage systems? No, those probably still qualify as part of the city....something deeper. Caves? Or a subway, that would make sense.]

Lead the way. [They can suss out details of the situation once they're more or less safe.]