Who almost played Dr. Rumack in "Airplane!" instead of Leslie Nielsen?

Who almost played Dr. Rumack in "Airplane!" instead of Leslie Nielsen?
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While he began his career as a leading man, count me among those who consider Leslie Nielsen nothing short of a comedic genius. His deadpan delivery didn’t just add a little something, they carried those movies — yes, even "Surf Ninjas."

We first got a taste of Nielsen’s comedic talent in a 1973 appearance on "M*A*S*H," but it was the 1980 summer spoof "Airplane!" that turned him into a beloved comic actor. That was followed by a successful run in "The Naked Gun" franchise, and then a bunch of movies that actually kind of bombed, but we’re ignoring all of that for now. 

Nielsen’s role as Dr. Rumack, who helps to discover that the entire crew and all passengers have become ill with food poisoning, delivered some of the most iconic lines from "Airplane!" and in comedic movie history. But the role was nearly played by someone else. Who was it?

Click START below to answer.