"The Yamaha Rhino started to rock and it tipped over on my left side, crushing my wrist," said Justin Miller, who lost his left hand after a Rhino accident in May of 2008.
Miller says he wasn't jumping sand dunes or careening around corners - just driving less than 15 miles per hour on flat ground when his 1,100-pound Rhino rolled over.
Miller told CBS News chief investigative correspondent Armen Keteyian that he was wearing a helmet, belted in and that he didn't break any rules.
Yamaha disputes that, citing a police report saying Justin was driving 20 miles an hour down a hill and hit a rock.
The Rhino has been a runaway hit in the off-road market since its introduction in 2003; more than 150,000 have been sold to date. It turns out no one tracks exactly how many people have been injured while riding in these recreational vehicles.
But CBS News has learned of at least 440 Rhino-related death and injury lawsuits across the U.S. - including Justin Miller's.
Miller said that if the rider were leaning left on a Rhino, "it would tip over."
The Consumer Product Safety Commission cites hundreds of reported injuries - including broken bones, crushed legs, arms and heads - often on level ground at relatively low speeds. The commission also cites a disturbing number of deaths.
"The public needs to be aware that already 59 people have been killed in these vehicles," said Inez Tenenbaum, head of the CPSC. "It's very high risk. This vehicle has a high center of gravity and it will turn over."
Last March the CPSC and Yamaha agreed to a voluntary "free repair" program. Yamaha temporarily suspended sales of all Rhino models and agreed to make a series of repairs to improve handling and reduce injuries. The CPSC told people to follow Yamaha safety guidelines, finding many cases of unbelted riders.
Still the new head of the CPSC says her agency's investigation is far from over.
"We'll continue to look at this, and if we have to take stronger measures, we will," Tenenbaum said.
Yamaha Motor Corp, which did $16 billion in sales overall last year, fiercely defends the Rhino. It argues virtually all accidents are caused by operator error - ignoring safety warnings, driving too fast on pavement, or failing to wear seat belts or helmets.
"I think there's just a lot of people out there who give people like me - my family - bad names and give these machines bad names," said Rhino rider Darren Thau. "There's a lot of stupid people."
Yet one video shows a Yamaha dealer employee moving a Rhino from one part of a dealership to another when it tips over.
Yamaha Dealership Employee Tips Rhino
Watch CBS Videos Online
Turns out, the potential for rollovers was well known to Yamaha executives. According to documents obtained by CBS News, just 15 months before its introduction at a testing ground in Kentucky, two riders rolled over in a prototype for the Rhino. The driver: a Yamaha president at the time. His passenger: the vice president in charge of Rhino Development who sustained a foot injury.
Today there are no safety standards for these so-called "side-by-side" vehicles. Right now, the industry is drafting a set of voluntary ones. Tenenbaum says that may not be enough.
"With the number of deaths that have already occurred, we're even thinking we should go to mandatory standards," Tenenbaum said.
Yamaha wouldn't provide someone to speak with us on camera so we went to their headquarters in Southern California. But despite repeated requests company lawyers ultimately decided not to let anyone speak to us on camera.
Yamaha did provide several off-camera interviews and answers to written questions. In statements to CBS News, Yamaha said: The Rhino "...is a safe, reliable and versatile vehicle...." and "...has won virtually every 'first-in-class award' and top safety ratings… and that the vehicles have been tested for thousands of hours and perform with a high level of customer satisfaction."
Certainly not for customer Justin Miller.
"A lot of people and a lot of kids before me have died," he said. "And if we had known that, we would have never bought this product."
Now, after seven surgeries, 17-year-old Justin Miller is on his way to college to study pre-med, hoping one day to become a doctor, specializing in prosthetics.
YouTube video of Rhino spill on sand
YouTube video shows Rhino spill in mud