Preventing damage

If I see a carboard box lying in front of my building, and I think that maybe someone might slip on it (actually, not very likely), can I throw it out in the garbage, or do I have to take into account that this might still belong to someone? Another point: if I moved it a little bit, and it really is considered a “hole in public domain”, did I now become the owner of that hole?  

Dear …!

1. If this box doesn’t really pose any real danger to people, then you don’t have to move it from its place. But there is a commandment to remove an item that is in a public domain if it can really cause damage.
2. If a person placed a dangerous item in a public domain, that person is obligated to remove it. And if this item wasn’t moved to some other place, and it caused damage in the place where the original owner placed it, then the original owner is liable for the damage.
3. The question whether a person who moved the dangerous item to a different location in public domain is liable for the damage that it caused is a matter of dispute. Therefore, if there is a specific question, then a competent rabbi should be consulted. He should be provided all the details of the case.

Tractate Bava Kamma, folios 6, 29b; Shulchan Oruch, section Choshen Mishpat, chapter 410