Having been an EMT and having gone to many suicide attempts, which some were successful, one has to wonder exactly what people are thinking about when they make the attempt. The one thing that I and others have learned from past experiences, unless they get the help that they need, they will make the attempt again and again, until they are successful. One of the biggest problems is that many times, that they will not reach out for help, because it isn't help with continuing their life that they are looking for, they are looking for a way out from under what they perceive as a burden that they can't handle.
My condolences for the loss of your friend, however, there is no reason for you to feel guilty, because he never reached out to you for help. We can only help those that ask for our help and truly want it. I also lost a close friend to suicide, and I knew that there was nothing that I could have done to stop him. I talked him out of it once, but when I went away for a week, he made his choice that was irreversible. There was nothing more that I could do for him. I did find an antique hearse for his funeral, since he loved old cars, and that gesture was appreciated by the family.
Junk