I'm so sorry for your loss. It's funny how all through nursing school the instructors or saying how you should not get "too close" to your patients. But you just can't not get too close. They become like family, and you become their family. If you don't get too close to your patients, it is more difficult to pic up those times when there is the slightest change that gives you the head up that something major is around the bend.
I was a CNA many moons ago. My first favorite who passed gave me warning that he was about to pass. But being a teenager I just didn't know it. He used to always say he was going to take me to the moon. One evening he was being very quiet. I asked him about our travel to the moon, and he replied "Well if you wanna go, we better hurry, I won't be here much longer." I laughed with him, gave him a hug and put him down for bed. I came back the next evening to find he had died in his sleep. I keep this story with me, so that I remember now as a nurse, those little clues. That way I can mention it to family in case they want to be there. It was sad that "Grandpa" was not able to be with family when he passed, but knowing the last person to put him to bed, was someone who loved him, helped me feel better.