Encourage your friend to talk to these people or a therapist. Continue to let your friend know that you care. Call a suicide hotline for help. Give the number to your friend. Encourage your friend to call.
Most areas have a local suicide hotline number.
You can also check them out online . Don't try to call their bluff, daring your friend to kill him or herself. Don't be a judgmental listener. Don't keep it a secret. Try to get your friend to go to professional for help or to call a hotline.