Building's liability and homeless - hypothetically speaking

Unnamed building has a policy to remove said homeless person from sleeping in the immediate vicinity of the building/area (like an outside alcove or a doorway). Management tells their security guard that's his responsibility to get the homeless person to move on. That security guard is a coworker of mine. He's reluctant to do this task. Not out of empathy but out of ... "that's not my job" mentality. Since, he's pretty new at this site? He should not take his duties for granted.

I suspect that the building has this policy in case the homeless person gets injured in his or her spot and the possibility the building and its management gets hit with a liability suit.

I plan on telling him something along the lines. Am I in the correct ballpark for why building management has this type of building security policy?

I know a city building and their management holds some liability when it comes to maintaining building adjacent sidewalks when it comes to keeping it clear and safe from ice and snow. A slip and fall would allow a victim to sue both the building and building management. But does this legal responsibility apply to a possible nonweather related injury? I'm certain if a brick fell off the building? The building would be liable for any subsequent injury or death in that obvious case.