There's nothing holding you when you drop 3/4 all the way down. Kinda like a runaway elevator. Picture being 22 stories high with your feet dangling only to unexpectedly free fall most of the way down until the ride catches itself near the end like a magnetic force.
Six Flags Magic Mountain has a ride that's higher called Superman the Escape that fires you up at 100 mph in a near right angle direction before gravity sets you rolling back backwards . However, you're on a roller track the entire time. Have no problem getting into that , for I've had done during the day and at night.
I've heard too many stories about the free fall coasters similar to Drop Zone , malfunctioning