While watching Jumanji, I came to the realization that we were never told how Alan's parents died. But something in particular stood out to me.
If you look at the tombstone in the movie, you can put together that Samuel was 70 when he died, and Carol was 61. For U.S. men, the average life expectancy is 76, while it's 81 for U.S. women. That's fairly close for Samuel, but way off for Carol.
We're told by the homeless man in the old Parrish shoe factory that Samuel started pouring all of his money and time into searching for Alan, and after a while he stopped coming into work. Alan's last words to his father were that he never wanted to see him again, which would be a huge burden to carry. It's possible that as time passed with Alan still missing, Samuel lost the will to fight for much of anything. This would certainly kill a man emotionally, and it's possible that he didn't take care of his own health while focused on Alan after all those years.
But then we look at the dates they died. Samuel's death was in May of 1991, and Carol's was unfortunately just three months later. They didn't die on the same day, so we know their deaths didn't happen on some Sheikh's yacht. They're awfully close together, and again, statistically Carol could have lived to be much older. She would have been all alone after Alan's disappearance and Samuel's death. Is it possible that she felt like she had nothing to live for anymore?
Sure, you could argue that this theory never happened, or better yet that it doesn't matter. They won Jumanji and everything was put back. But Alan and Sarah still remembered it all. Perhaps you could say that it wasn't the lion, monsoon, or venomous spiders that made Alan realize how important his relationship was with his father was, but knowing how much Samuel really cared after discovering the tragedy that happened to his parents.