I didn't know the man personally. Mark always hated his guts and gave me all of the reasons why. As his friend I could only know what he told me about it, and therefore share the disregard he felt for his father. Even though he lived right there on the South Side, Mark never visited him. He would go out of his way to drop his brother off there or visit his cousin around the corner and deliberately not go into his father's house.
None of them really talked about their dad much, even Louie who respected him to some extent and even lived with him for awhile. It was always just one of those things you know about your friend's family life, not a big deal but in that little roledex of facts that you knowing about shows how close you are to a person. I knew I would never meet him. Mark never seemed to care.
But now that his dad unexpectedly died of a heart attack, he's having alot of trouble dealing with it. I mean obviously its a huge traumatic event when a parent dies, even one you didn't see often. But there's some weird added element of guilt or lack of closure when there was a grudge between you and the deceased. Although Mark said he never wanted to reconcile with his father, now he is left wishing he had and realizing he'll never have that chance now.

Few people _really_ hate parents enough to disregard their deaths. In fact, most of the time it is harder for those that "hated" their parents because then they feel very guilty for never coming to peace with them.

Sometimes, the best thing to say is nothing at all. Or if you don't know what to say, then acknowledge this; "I don't know what to say" can be oddly comforting in its own right. Either way, what's important is to let the other person lead for a short while, and see if you can pick up cues as to what to do from their actions.

It took me years to learn this one, and I screwed up a more than one close friendship by not realizing it sooner. Trust me, it's worth knowing.