I had a coworker many years ago when I still worked in Telecom who went through with it. Our supervisor went to his apartment when he hadn't shown up for work or called in and found him. When a timeline was put together we figured out that I may have been the last person to speak with him - I was working midnights taking calls from customers and he had called in, he was cheerful and talkative and I talked to him for a little while until calls started backing up and I had to go (I was alone on the phones during that stretch). That messed with my head for a LONG time after.