DOSWELL, Va. (AP) _ A man who died after falling from a roller coaster had partially wiggled out of the shoulder harness holding him in the ride, investigators said.

Timothy Fan, 20, died Monday night after falling from the Shockwave, a stand-up roller coaster at Paramount's Kings Dominion, about 20 miles north of Richmond.

A preliminary investigation showed the ride was operating as designed when Fan fell and that his safety restraints did not fail, the Hanover County Sheriff's office said Thursday.

Betsy Moss, a spokeswoman for Kings Dominion, said the ride's double-restraint system, which includes a shoulder harness and a waist-level restraint bar, was found locked in place after the train pulled to the platform.

Gary Tomei, an attorney representing Fan's family, questioned how someone could get out of restraints on a fast-moving roller coaster.

``This thing is going 50 mph. You're subject to the centrifugal force. ... How are you going to get yourself wriggled out? Is this Harry Houdini here?'' he asked. ``They didn't check him in right, or one of their safety precautions failed.''

No lawsuit had been filed as of Thursday evening.

The Shockwave and two other stand-up roller coasters at Paramount amusement parks were temporarily shut down after the accident.