@Great Mara Under New York law, property owners are liable for injury to anyone, trespasser or not, for injuries suffered as a result of dangerous conditions reasonably foreseeable by the owner.
Your story about the skylight is complete bs. A property owner in New York has no reason to suspect his skylight cannot withstand the weight of a boot. He lives in New York, he gets snow. He would know if a skylight needs to be replaced because his apartment would be full of snow one winter day. Furthermore, one does not expect people to walk around his roof, and one has no reason to protect his roof from people falling through openings in the roof and injuring themselves. There is no duty of care and there is no liability.
Link to court decision please, or quit flapping your mouth about things you don't know.