The right thing to do would be dialing 911, which is the line designed to deal crises. As a friend, one may feel compelled to try lending some comfort to a cared person who is going through issues; however, we may not always be qualified for this and there is a possibility we do more harm than help, particularly if our friend does mean to hurt him or herself. By dialing 911, the case could be taken on by behavioral specialists trained to deal with situations like these. The police should be contacted when a clear and present threat to the person and/or some other ones in the surroundings is clear and requires law enforcement.