The van fire that killed one young girl and critically injured her sister while their mom shopped in a Fridley Walmart earlier this week has renewed the debate about how young is too young to leave children alone.

Their mother, Essie Mc­Kenzie, is facing scrutiny from Anoka County child protection officials even though she didn't start the fire. She said she was shopping for less than an hour after making an early morning trip to the airport.

Meanwhile, authorities say Roberto Hipolito started the blaze, which spread from his van to the neighboring one in which the girls were sleeping, by placing a still-hot cook stove in his vehicle. He is charged with second-degree manslaughter and negligent fire.

"First and foremost, our prayers and concerns are with Ms. McKenzie and her family," said Anoka County Sheriff's Office Lt. Daniel Douglas. "When you look at this whole situation, what an incredible and unfortunate sequence of events."

Minnesota law doesn't clearly define ages or milestones a child must reach to be left alone, leaving counties to rely on guidelines laid out by the Minnesota Department of Human Services (DHS). Those generally advise that children under age 8 shouldn't be left alone and children under age 11 shouldn't be left to care for others.

But there can be different factors — from children's maturity to the location where they are staying — in almost any case.

The ambiguity poses a challenge even for mandatory reporters, including police and teachers, St. Paul police Sgt. Mike Ernster said.

Officers responding to a call of an unattended child will assess the capability of the child, how long they were left alone and if there are additional signs of neglect or possible abuse, Ernster said. For example, were they in a car or at home? Were they strapped in? Was heat a factor? What was the parents' attitude when questioned?

Still, it feels as if laws regarding leaving pets in a vehicle are more clear-cut than laws around unattended children, he said.

"There are a ton of factors," Ernster said.

Jenny Hanlon, a teacher and educational consultant who has developed a class called "Home Alone" for children ages 8 to 11 and their families, has shared her lessons about the state guidelines and what children should do on their own with schools across the Twin Cities.

"So many people don't know what the rules or guidelines are," Hanlon said.

What is reasonable?

Minnesota criminal and child protection statutes don't lay out specific ages when kids can be left unattended because emotional development varies greatly among children. Some kids may be ready earlier, and some may need supervision into their teens.

But in the Fridley case, the DHS guidelines prompted Anoka County to step in. Ty'rah White, who died Tuesday of smoke inhalation and burns, was 6. Her sister Taraji White, age 9, is still hospitalized.

"The child protection guideline is a 9-year-old can't be left to care for younger children," said Douglas, whose office referred the case to child protection.

Many counties, including Hennepin, Anoka, Dakota and Ramsey, lean on those DHS guidelines, which are based on brain development. Those say children ages 8 to 11 can be left alone for a short period of time but shouldn't be responsible for watching others; a child age 11 could watch a younger child for a limited amount of time.

"It's not black and white," said Rick Morrissey, a supervisor in Dakota County Child Protection, speaking generally. "There are some kids who are 10 or 11 who can't be home alone" due to disability or developmental delays.

Hennepin County officials wouldn't comment on another county's case but said they try to help families understand the laws.

"What we look for in child protection is, did the parent take reasonable efforts to protect that child?" said Jennifer DeCubellis, Hennepin County deputy county administrator. "It's looking for reckless endangerment or neglect a person could access in advance."

Attorney Eric H. Anderson, who represents parents in child protection cases, said he believes the child protection referral in the Fridley case is a "cruel" overreach.

"It's absurd. She just ran into Walmart," Anderson said. "To call her parenting into question for just going to Walmart, it doesn't seem right."

Anderson said it's further evidence that "anyone and everyone can get dragged into their [child protection] web."

Preparing families

Hennepin County's DeCubellis said sometimes the solution to a child protection complaint involves helping families find child care, especially for emergencies or unexpected snow days.

"For families on the edge of poverty, parents are thinking, 'I've got to get to work,' " she said. "We want to make sure families are not making those hard decisions."

When parents do decide their children are ready to be home alone, Hanlon said she talks with families about making sure kids know how to call their parents with questions or call 911 in an emergency. She also advises parents not to leave children alone when they are sleeping because they may not hear smoke alarms.

Expectations for child supervision have changed dramatically in a generation's time, she said: "A lot of us adults have very different memories of being home alone and running free in the neighborhood."

But she encourages parents to resist the urge to cut back too far on children's independence.

"It's not healthy to helicopter our kids either," Hanlon said. "I am a big proponent of letting kids have freedom and responsibility. I think we are hindering them by not letting them have that."