At a party thrown by Tyrone Power and wife Annabella, David Niven and his wife Primmie–who had just moved to America six weeks before and who had two children–were playing a game of sardines, aka hide and seek. The house had originally belonged to Al Jolson and Ruby Keeler; among the other couples at the party were Gene Tierney and Oleg Cassini and Rex Harrison and Lili Palmer (all of them destined for unhappy lives themselves).
In the dark, Primmie opened a door to what she thought was a powder room. As it turns out, it was the door to the cellar, and she fell backwards down a flight of very steep stairs. She died the next day, aged 28. Some say Niven never recovered.