Aww, no! I doubt you will kill them.
Well actually, the picture didn't have any plants at the base of the tree. Just one sinle bromeliad in the pot and the rest of the pot is empty (that doesn't look all thst interesting being empty like that).
Wow, that is sad. I do feel sorry for the kid, but then again, I don't feel that excuses his behavior whatsoever. That does sound odd about the plant. Did you ever allow him back in your house after that? Or his Dad?
Planto