Investigators say a driver’s decision not to have a flat tire fixed led to the deadly flames that consumed her minivan on an Eden Prairie highway and forced her to flee the burning vehicle while it was still moving.

The State Patrol released its conclusions this week about the chain-reaction circumstances surrounding the van fire that sent belching smoke skyward above Hwy. 5/212 April 25 and created a lunch-hour tragedy in an area packed with stores, restaurants and other businesses.

Susan J. Clark, 66, of Eden Prairie, was taken by ambulance to HCMC, where she died 45 minutes later from burns and other injuries.

In the weeks since Clark’s death, her three children, two sisters and other relatives have wondered why the vehicle caught fire in an instant.

“I hope we can find an answer for some closure,” Clark’s sister, Kathleen Raab, said several days before the patrol disclosed its findings.

The patrol determined that a piece of the left rear tire flew up and damaged the space just below the fuel cap, igniting a small amount of gasoline in that spot.

The burning van kept moving east, grazed a median barrier and veered onto a grassy area, where Clark abandoned it as it kept rolling.

Patrol Lt. Tiffani Nielson said Clark visited a Midas outlet earlier that afternoon and received an estimate for new tires and asked about having her flat tire fixed. She told a store employee she wanted to check with someone before deciding what to do, Nielson said. She then drove off on the flat tire.

Bob Ross said Thursday that Clark, a longtime friend, called him about the price quoted for four new tires. He said he thought it was a bit steep and arranged to meet her at another tire store to ensure that “they didn’t take advantage of her, being a woman. ... I waited over there for quite a while and heard a lot of sirens.”

Clark was traveling in the direction where Ross was waiting when the flames and smoke engulfed her van.

Greg Clark said the “major question” has been why his mother chose to drive on a flat tire. “It seems crazy that she would drive there on a flat tire and then not get it fixed,” he said. “What I think happened [is] she had her dog at Midas and then made it back home, dropped the dog off and then headed back ... when the fire occurred.”

The son added that Clark was dealing with early onset dementia and “that may have had some influence on her decisionmaking abilities.”