A 21-year-old motorist was run over and killed after getting out of her car following a two-vehicle fender-bender on a northeast metro interstate, authorities said Thursday.

The four-vehicle incident started unfolding shortly before 11 p.m. Wednesday on southbound Interstate 35E at County Road E in Vadnais Heights, according to the State Patrol.

Killed was Jennifer L. Ehnstrom, of Chisago City, Minn., the patrol said. Slightly hurt was Sue Vang, 22, of St. Paul, the driver who hit Ehnstrom. The two other motorists were not injured.

"Tragically, a young woman died after being struck outside her vehicle following a crash she was involved in," Patrol Lt. Eric Roeske said. "Although every situation is unique . . . your best option is to remain in your vehicle with your seat belt on and get your vehicle to a safe place."

But if your vehicle is too badly damaged and won't move, Roeske said motorists should call 911, stay in the vehicle and wait for help to arrive. The lieutenant said he did not know whether Ehnstrom could have driven her car out of harm's way.

"It's not uncommon for people to want to get out of their vehicle and see what the damage is," he said.

The State Patrol, in reaction to Ehnstrom's death, released on Thursday afternoon to its nearly 5,000 Twitter followers links to an "In Case of a Crash" brochure and an instructional video.

The brochure emphasizes getting your vehicle out of the way, not walking in the traffic lane and staying seated. "You are safest inside your vehicle," it declares.

According to the patrol:

Ehnstrom's car collided with a Ford pickup driven by 83-year-old Leo J. Koran, of St. Paul. Both vehicles struck the median wall. Ehnstrom's car was partly in the center and left of the three lanes.

She and Koran got out of their vehicles, and Vang's Toyota pickup struck Ehnstrom as he drove by. Ehnstrom died at the scene.

The Toyota then hit a minivan that was pulled over with 42-year-old Katherine Skogsberg, of Hugo, behind the wheel.

"I was in the second lane, and [Ehnstrom] was on my right," Koran said Thursday morning, saying he had his cruise control set at slightly below the posted speed limit.

"All of a sudden, bang, bang, bang. 'What the heck is going on here?' " he continued. "The airbag comes out and hits me in the head. . . . I was facing north, instead of the way I was going home."

Ehnstrom came up to his pickup, where Koran was still inside. "I said, 'Am I the one you hit?' "

The next thing Koran said he remembers was being in the back of a squad car and hearing that the woman had been run over.

Paul Walsh • 612-673-4482