Asking a person if he/she is thinking of committing suicide is not going to push them toward death. In fact, asking that question might open the door back toward life.
So -- if you know someone who appears depressed -- not just kind of down in the dumps -- but truly depressed, it's not only okay to -- it's important to -- ask about suicide.
For example -- I'm noting that you seem really depressed and I'm worried you might be thinking of killing yourself. Do you want to talk?"
Kids have always been teased about anything other kids can grab hold of -- anything that makes the kid being teased different. Things, though, seem to have gotten a bit more intense with the campus harassment of LGBT students. Technology has made it easier to be vicious and even anonymously vicious.
All of which makes it more essential to talk to people who seem at risk -- and talk in any way possible -- in person even.
Suicide can be prevented and sometimes the most effective prevention methods is simply to ask the question.