Complex sentence: In an event unprecedented in the history of the Oscars, "La La Land" was incorrectly announced as the Best Picture; after a few minutes the error was corrected and "Moonlight" was declared the winner.
Split into simpler sentences: In an event unprecedented in the history of the Oscars, "La La Land" was incorrectly announced as the Best Picture. After a few minutes the error was corrected and "Moonlight" was declared the winner.