Simplify the following text for a Grade 8 native English-speaking person.
Original: The grand opening of the Olympic Auditorium was on August 5 , 1925 , and was a major media event , attended by such celebrities as Jack Dempsey and Rudolph Valentino .
Simplified: It opened on August 5 , 1925 , and famous people like boxer Jack Dempsey and silent film actor Rudolph Valentino were there .