Officials of the company that operates Kings Dominion in Virginia said they have temporarily shut down seven rides at their five amusement parks in North America to review their safety after two fatal accidents in the past week.

The rides under review include the Shockwave roller coaster at Paramount's Kings Dominion, where a 20-year-old New York man fell to his death Monday night, and two other stand-up roller coasters also designed by Togo Japan Inc., said Susan Lomax, a spokeswoman for Paramount.

Also closed temporarily is the Drop Zone ride at a Paramount park in Santa Clara, Calif., where a 12-year-old disabled boy fell to his death Sunday. Three similar rides in other Paramount parks are now shut down.

Lomax said that there is no evidence of a mechanical malfunction in any of the seven rides but that they will remain closed until investigations into the incidents are complete.

Kings Dominion officials have said that Timothy Fan, the Long Island City man who was killed Monday, must have taken some action that contributed to his fall and that there was no evidence of a problem with the safety harness or of an error by the operators of the ride.

Gary A. Tomei, a New York attorney representing Fan's family, said yesterday that he does not see how the ride can be safe if someone can fall from it while it is in motion.

"As far as I am concerned, once they have locked you in that machine, you're not supposed to get out unless you're Houdini," Tomei said.

Fan, who was supposed to begin his junior year at Hunter College in Manhattan tomorrow, arrived at the park Monday afternoon with a tour group, Tomei said. The group had planned to stop at a second amusement park before heading to Virginia Beach.

Passengers on the Shockwave, a 13-year-old steel roller coaster, stand up for the two-minute ride. The 24 passengers in each train go through two loops, a single inverted loop that takes riders upside down, followed by a side spiral.

Fan fell near the ride's end as the train came off a straightaway, slowed down and went into a 180-degree curve, said Betsy Moss, spokeswoman for Kings Dominion.

The Shockwave's track is about a dozen feet off the ground at that point, said parkgoers who have ridden the roller coaster. Underneath is a slim concrete maintenance walkway and a grassy area.

Moss said the Shockwave's double-restraint system, which includes a shoulder harness and a waist-level restraint bar, was found to be locked in place after the train pulled into the station.

Roller coaster experts familiar with rides like the Shockwave said their safety record is impeccable. Leonard Cavalier, executive director of the National Association of Amusement Ride Safety Officials, said stand-up roller coasters are equipped with redundant safety mechanisms that would prevent even a broken harness from endangering riders.

"I don't know of any cases where a restraint has failed on one of these inverted rides," Cavalier said. "But if you were actively trying to get out, you could probably manage it if you worked hard enough."

Tomei said he has heard no account that would lead him to believe that Fan was disobeying the ride's rules. "As far as I understand, this type of ride is supposed to be safe in all aspects. When you have someone who is locked into a roller coaster ride that is supposed to have a number of safety devices on it, it is not acceptable that you go flying out for any reason."

Richard Bartell, chief building inspector in Hanover County, where Kings Dominion is located, said the Shockwave was inspected in July and had no problems.

"We have never had an issue with that ride," he said.

Steven Thompson, who leads the 330-member Mid-Atlantic Coaster Club and has ridden more than 400 roller coasters, said the Shockwave's safety devices are nearly identical to those on many other roller coasters.

"For the life of me, I can't imagine how a normal individual could manage to extricate themselves from that particular restraint device," said Thompson, 51, of Springfield.

Several people who have reviewed roller coasters for one of the many Internet chat rooms devoted to the rides said they were bothered by the restrictiveness of the safety measures on Shockwave. Some said the security features take away the excitement.

Andrew Winner, 15, of Westminster, Md., said he has ridden the Shockwave several times and found it to be a "very calm" ride in which he has always felt safe.

"The restraints on Shockwave are top of the line," he said in an interview. "I have always felt secure in them and never feared injury on the ride. In fact, I usually ride Shockwave with my hands high in the air."