Did they die in the house as a result of something wrong with the house (poison gas or something)? If the house did not cause the death, bur rather the occupant died of natural or unrelated causes, I don't see why you would need to mention it.
In my area, most houses are over 100 years old. I assume perhaps several people have died in them, but I've never been specifically told that.
Of course, I've never been asked . . . if someone asked me outright, and I knew, I probably wouldn't lie about it.
What is your concern? That people won't want to buy the home?