Will and everyone else who knew Mike, please remember that this had nothing to do with you. There was nothing you could have done differently; there was nothing you should have picked up on; there was nothing for you to take personally. Everything he ever did, good, bad, or indifferent is stil valid -- this only changes the future -- but this was about him and how he was feeling inside, and what he chose to do about that.
When something this shocking happens, looking for a way to wrap one's mind around it is as normal as the pain, and to that end our minds often wander to recent events looking for some meaning, some understanding, something, anything that we can touch. I am so sorry for your pain. Please try to take some time for yourselves and maybe get together and talk. It's a lot to take in.