A good friend of mine had a similar thing,called a "sub-arachnoid vessel burst" or something. Luckily for him the blood vessel sealed on its own. He had a sudden intense headache, collapsed, went to ER. Brain scan showed burst vessels and hemmoraghing, follow-up test showed it almost completely gone. He went for 6 month followup last week, there is no sign of any permanent damage. The neurologist called him a medical miracle.
I'm sorry for the loss of your friend. As others have pointed out, it can be anyone at anytime. We should all try to live life to the fullest and appreciate the people around us because it can end in a flash.