Complex sentence: In 1999, shortly after the tragedy at Columbine High School, which caused a radical shift in educational and social behavior inspiring two filmmakers, Darrin Fletcher and Chet Thomasto create a new teaching curriculum through the medium of film and the internet.
Split into simpler sentences: In 1999, a radical shift in educational and social behavior took place after the tragedy at Columbine High School. This tragedy also motivated two filmmakers, Darrin Fletcher and Chet Thomas to create a new teaching curriculum through the medium of film and the Internet.