The families of two women who burned to death after their Polaris four-wheeler tipped over last year have sued Polaris Industries, alleging that unsafe fuel pump and gas cap designs were responsible for the tragedy.

Polaris, under fire for a string of recalls involving its ATVs, denied on Friday that its design contributed to this particular crash, saying the challenging mountain trail where the women drove — called Tip-Over Challenge — was the cause.

"The safety of our riders is our absolute top priority. We are saddened by last year's tragic accident and offer our deepest condolences to the riders' families," the company said in a statement. "The lawsuit and accident involve a rollover crash in an expert riding area. Our investigation and all available information confirms that the accident was not caused by any defect."

The wrongful death lawsuit, delivered Thursday to Hennepin County District Court, was brought by Kim Schwitzer, the mother of victim Destiny Dixon, and by Ashleigh Swann, the daughter of victim Debbie Swann. Witnesses Greg Priore and Floyd Ingram, who were part of the victims' riding group, also joined the lawsuit as plaintiffs.

Court officials said Friday that the families' lawsuit had been received and will be officially filed and assigned a case number in the next few days.

Debbie Swann and Dixon were killed Sept. 2, 2016, after the 2010 Polaris Ranger 800 they were driving tipped over slowly while they were ascending a steep trail in Moab, Utah.

The complaint, citing an investigation by the Sheriff's Department there, said when the slow-moving vehicle tipped over on the passenger side, the gas cap hit the ground and broke off, releasing "a lethal amount of gasoline which then ignited."

While Priore and Ingram were rushing to help, the vehicle burst into flames, instantly killing the occupants, the complaint said.

"Within a few seconds, the Ranger was completely consumed in extremely hot and high flames, leaving no chance for Destiny Dixon and Debbie Swann to escape. They were burned to death before they could release their seat belts," the lawsuit said.

The lawsuit acknowledges that the crash took place on a "challenging section" of the "widely used four-wheel-drive trail" but said the fire deaths never would have occurred had it not been for the faulty design of the 2010 vehicle.

Jeffrey Eisenberg, the Utah attorney representing Ashleigh Swann from Washington state and Schwitzer from Arizona, said the Ranger recreational vehicle lacked two key safety features that are standard in passenger vehicles. In passenger cars, fuel pumps shut off automatically in the event of a rollover. Gas caps also are fully recessed and covered by a door so they are protected from impact.

"There were no such protections built into the design of this Ranger vehicle," ­Eisenberg said, noting that the 2010 Ranger model was designed with an uncovered gas cap that protruded slightly from the vehicle.

The lawsuit also alleged that the 2010 Ranger model had a fuel tank that was located too close to the vehicle's occupants and lacked certain venting and spill-prevention ­features.

"The fire occurred due to defects in the design and manufacture of the vehicle, which render the Ranger unreasonably dangerous," the complaint said. It further argued that Polaris knew about the alleged design flaw and yet there was a "deliberate and reckless refusal to remedy known deficiencies with the Ranger's design or warn the occupants of the hazards associated with its use."

The lawsuit accuses Polaris of product liability problems, negligence, manufacturing flaws, breach of warranties and of failing to warn riders about the risks.

The families are seeking more than $50,000 in damages.

The lawsuit is the latest of several affecting Medina-based Polaris, a $4.5 billion manufacturer of ATVs, snowmobiles and motorcycles. During the past two years, Polaris has recalled more than 338,000 vehicles because of various problems, most tied to potential fire hazards. The company's vehicles have been involved in 247 fires to date.

Past mechanical problems tied to prior recalls have no bearing on the September Utah accident, company officials have said.

Dee DePass • 612-673-7725