I once volunteered for the Suicide Prevention Service of Santa Cruz Count, in California.
I never lost anybody.
All I ever required to convince someone to disarm the implement of their own destruction, get a good night's sleep then consult a mental health professional the very next day was an hour or so of "Active Listening".
I quickly came to the conclusion that most suicidal people get that way because they feel no one ever listens to them.
Active listening is very helpful in many other situations, for example when someone is violently angry active listening can lead them to be happy and friendly.