Rollercoaster

Rollercoaster is a movie starring George Segal, Timothy Bottoms, and Richard Widmark. A blackmailer threatens to sabotage roller coasters at various American amusement parks if he isn't paid a huge ransom.
A young terrorist kills and injures patrons of a Norfolk amusement park by placing homemade explosives on the track of one of its roller coasters. After staging a similar incident in Pittsburgh, he sends a tape to a meeting of major amusement park executives in Chicago, demanding $1 million to make him stop.