Horrible. RIP. Hopefully his family can gain a modicum of peace too.
Such a tough thing and it's only compounded by and made more difficult to detect by how we live now- largely with our heads in our phones. If you look at Phil's Twitter it essentially looks completely normal all the way through the end.
Sometimes (maybe even often) there's nothing you can do but perhaps we need to be better listeners in our reduced actual face to face or verbalized interactions with our friends and family?
I'm personally now just reflecting upon some interactions I had with a friend in the last few weeks. I gaffed it off as the guy maybe just being emotional about some things after we had a few or 15 beers but now I'm definitely going to at least try to follow up just in case he actually was trying to reach out for more than just an ear.