Someone wanting to kill themselves is not something that should be taken lightly. If someone comes to you saying they want to kill themselves step in immediately. Ask them calmly and respectfully why they are considering such a drastic choice. Without being too forceful, try and have them open up to you so you can try to help them out and find a better outlet for their choice. Be respectful in your tone and say what you feel is right to get them the help they need.