Rollercoaster

An unnamed man (Timothy Bottoms) sneaks into Ocean View Amusement Park and places a small radio-controlled bomb on the tracks of the park's wooden roller coaster, The Rocket. The bomb detonates, a coaster train derails, killing and injuring the riders. In Pittsburgh the bomber causes a fire on a dark ride at another park. The FBI rejects Calder's hypothesis but decide to investigate anyway because the ride is scheduled to debut on July 4, when park attendance will be at its highest for the season.