Went back and did some more reading. The post that was on the (his?) church's Facebook page that had information on "the attack", was posted around 09:00 of Thursday. So "the attack" apparently happened overnight, the 16th/17th.

If I remember correctly, by that afternoon, he was "on his way" down to see him then, after apparently resolving the dilemma of whether or not to go.

From another Facebook post of Mark's, his father "went home" Friday evening. And from his first post here, and other Facebook posts by Mark, he died Saturday at noonish.

I think I have the story right, for now, until it changes.