The average opening for restraints on the seats on the 430-foot (131-meter), free-fall amusement park ride located in the heart of Orlando's tourist district was 3.3 inches (8.3 centimeters). However, the opening of the restraint for the seat used by Tyre Sampson was as much as 7.1 inches (18 centimeters), and the one for another seat was 6.5 inches (16.5 centimeters), according to the report commissioned by the Florida Department of Agriculture, which is investigating the accident.
VIDEO: Witness recounts moments after teen falls to his death from Florida amusement park ride
Sampson was only 14 but already 6 feet, 5 inches tall (195 centimeters) and well over 300 pounds (136 kilograms) when he slipped out of his seat as the ride plunged to the ground at speeds of 75 mph (about 121 kph) or more.
An inspection of the seats showed that sensors used to activate safety lights on the two seats, indicating the harness safety restraints were in place, had been adjusted to allow for the wider openings. As the ride slowed down, Sampson slipped through a gap between the seat and safety harness, the report said.
"The cause of the subject accident was that Tyre Sampson was not properly secured in the seat primarily due to mis-adjustment of the harness proximity sensors," said the report from Quest Engineering and Failure Analysis, Inc.
The Orlando Free Fall ride, which is taller than the Statue of Liberty, didn't experience any electrical or mechanical failures, the report said.
The release of the report marks the initial phase of the investigation into the teen's death, and "we are far from done," Agriculture Commissioner Nikki Fried said at a news conference in Orlando.
The report said there were many other "potential contributions" to the accident and that a full review of the ride's design and operations was needed.
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The video featured above is from a previous report.
ABC News contributed to this report.