Death of an actor which affected the final film

Sometimes actors die while a film is being made.  Movie studios and directors will often find creative solutions to finish the film without their actor.
Research at least one interesting story and explain it in your own words.  Comment on how effective (or how bizarre) the solution was. Feel free to discuss how else these decisions affected the film, the film's legacy, or the actor's legacy.


Oliver Reed, Peter Sellers, Heath Ledger, Paul Walker, and many many others.