Suicidal Thoughts Support

Hi all. I’m here to help my bf deal with depression and suicidal thoughts. He has always told me that he used to have these thoughts however it was a rare one in a while occurrence. However in the recent week he’s been having those thoughts every hour where he’s contemplated getting a gun and ending it. He got this idea from reading it somewhere it seems. I’m feeling very helpless as I am not sure how to help him as I’m in a long distance relationship with him. His thoughts have been stronger this past week. His close friend who also struggled with mental health passed away this week due to an accident(but could be suicidal as it was a drowning). I am not sure if that triggered this how ever he is not willing to acknowledge that it affects him. Any help and advice is welcome. Please tell me what I can do to help him or maybe have him introspect the root cause of this? Please I will be forever grateful!