One of the best posts ever here on HN on a difficult topic.

Lots of personal experience here (family). The suicidal 'mode' needs to be interrupted before death. Usually it lasts only an hour or two.

Helping one interrupt that mode is a learned skill that is very effective, and relatively easy to do.

This isn't universal of course, just my experience. If anyone reading this suspects someone is suicidal and they don't answer the phone at a time you know they are at risk, go see them asap. You might save a life.