Roller coasters don't have to reach extreme height or speed to cause a fatal accident. Take Willard's Whizzer, which peaked at just 70 feet (21.3 meters) and clocked in at a paltry 42 miles per hour (67.6 kilometers per hour). It was so tame that when it was first constructed in 1976, its cars didn't even have restraints [source: Besoyan].
The incident occurred on March 29, 1980, when a teenage boy was stepping onto the ride. Without warning, a second train came up behind the one he was boarding and rammed it. The impact threw the teen onto the tracks where the runaway train crushed his chest and abdomen. Eight others were injured in the accident, one of five fatal incidents in the park's history [source: Kaplan and Nelson].
Because the second train breached several automatic safety systems, investigators pinned the blame on an electric signal that disrupted the roller coaster's computer [source: California Research Bureau]. In an effort to rejuvenate the ride's image, the park put seatbelts in the cars and renamed the ride, simply, Whizzer. Nevertheless, the park eventually disassembled Whizzer in 1988.