Depression is a terrible thing and sometimes families and friends don't know it's as bad as it is, or the person is really good at hiding it. My sister committed suicide and I knew she was ill, but couldn't leave the kids (age 3mo and 17mo) and work to live with her out of town. Of course after the fact, I wish I had, but I think she just would have found another way later. And it's easy for THEM after the suicide (and they think their family is going to be happier or better off without them), but the family really suffers. Nobody knows what to say, nobody knows what to do (for the family).
If you even think somebody is depressed (more than the "I got a bad grade on a test or my parent yelled at me/my boyfriend/girlfriend dumped me"), grill them about it. Are you thinking of killing (hurting) yourself? (do they have a plan on how to do it - if the answer is yes. A plan is BAD). Get them talking and get them help. Maybe not quite as blunt as just asking, but not far from it. And this poor guy might have been getting help. My sister was and it didn't help enough. I hope the family is doing ok. It's a very sad thing and leaves family and friends guilt ridden for years.