Billy Crystal -- Nora Ephron Changed My Life Forever

Billy Crystal -- who starred in one of Nora Ephron's greatest films "When Harry Met Sally" -- is crushed by her death ... saying, "I am very sad to learn of Nora's passing. She was a brilliant writer and humorist."

Crystal issued a statement shortly after the Hollywood icon died, adding, "Being her Harry to Meg's Sally will always have a special place in my heart ... I was very lucky to get to say her words."