Conversation so far:
What happened to Katie Couric on ABC News?
Katie Couric was a special correspondent for ABC News
What kinds of things did Katie Couric cover?
News
Was Katie Couric in New York during that?
Yes
Has Katie Couric received any awards?
Katie Couric received the Walter Cronkite Award for Journalism Excellence for the interviews
Are there any other interesting aspects about Katie Couric's article?
In 1989, Katie Couric joined Today as national political correspondent, becoming a substitute co-host

Question: Why was she subsititing for her?
Self-contained rewrite: Why was Katie Couric subsititing for Norville?