I'm sorry to hear of his loss and condolences to his friends and family.
Life really is short and it's really unfortunate the events that happen and things take a turn for the worse. I realise this early on in life thus have learned to appreciate the people around me, certain situations, and realising that nothing is forever. It saddens me the realities of life, it really does.
Make the best of your times together. Time really doesn't wait for people.