For now, memorial balloons and flowers dangle from the chain-link fence that 6-year-old Kallie Palmer climbed before being struck by an SUV and killed on Interstate 35W.

This fall, the Minnesota Department of Transportation will replace the fence, which is less than 5 feet tall, with a 20-foot noise wall. Plans for the wall, part of an extension of the MnPass lanes through southern Burnsville, have been in the works for months.

The wall is meant to mitigate noise, not serve as a safety mechanism. But in the wake of Kallie's death, neighbors can't help but wonder.

"It's something that didn't have to happen," said Florence Freiderich, who walked out of her house, the closest to the fence and the freeway, and saw the commotion as emergency personnel swarmed the scene Friday night.

Lt. Eric Roeske of the State Patrol said investigators are still trying to piece together what led Kallie to the southbound freeway lanes near McAndrews Road.

They know that a group of five neighborhood children, all of them between ages 5 and 11, had climbed the fence and begun playing on the other side near the freeway. And there's no evidence that Kallie ran into the road while chasing a ball or toy.

"It sounds like they were just playing on the side of the road," Roeske said. "I don't know if they just got closer and closer and closer to the edge and she darted across."

She was struck by an SUV, driven by a Cold Spring man, at 7:15 p.m. in the southbound lanes.

Roeske said he couldn't recall a similar case in his 11 years with the patrol. "It's a real tragedy," he said.

Darren Smith of Burnsville said he was driving home about 7 p.m. Friday when he saw a child in dark-colored winter clothes jumping up and down by the freeway near McAndrews Road, arms waving.

"How could a kid be on the freeway?" Smith said he thought to himself. "It's just terrible. A nightmare."

MnDOT spokeswoman Christine Krueger said the standard height for a fence near a freeway is 60 inches. The fence that Kallie crossed, which the city says is owned by MnDOT, is visibly shorter than that.

MnDOT plans to begin construction of the wall, which will run from Burnsville Parkway to McAndrews Road on the western side of the highway, this fall. It's one part of a project that will extend the northbound MnPass Express Lane, which currently begins at Hwy. 13 and runs into Minneapolis, down to Southcross Drive.

Neighbors have long talked about walls to dampen the noise, but apparently hadn't noticed trouble previously with people climbing the fence.

"I've never seen anybody near that fence, ever," Freiderich said. Two other neighborhood residents, who asked not to be named, said they haven't noticed children climbing the fence or playing on the freeway side.

At Vista View Elementary School, where Kallie was a first-grader, many students spent time Monday making cards for her family. Two teachers also are assembling a scrapbook, with pages written by her classmates.

"It's just been a state of shock for all of us," said Principal Susan Risius.

The school district's crisis response team was on hand all day, and staff will be available to talk with student as long as they are needed.

Risius said many students remembered Kallie for her constant smile and bubbly, affectionate personality.

"Kallie was just one of those little girls that just touched your heart," Risius said. "She just always had a smile, a big smile, no matter what happened."

Katie Humphrey • 952-882-9056