A Chisago County family is grieving their 3-year-old boy, who was killed over the weekend when a parked ATV tipped over on top of him.

The tragedy occurred in a matter of minutes after Landon Erickson wandered outside his rural Franconia Township home Sunday afternoon. The little boy was trying to move a child's-size ATV off a slope when it rolled on top of him, the boy's family said.

Landon's death is a severe blow to a family already reeling from loss. On Thursday, they will return to the same Forest Lake funeral home where they mourned Landon's grandfather, who died in a car crash a little more than three months ago.

"It's pretty sad around here," Jerry Dimmen, Landon's great-grandfather, said Monday. "He had a warm heart, was happy and quick to smile."

Dimmen's 52-year-old son, Dean, died Dec. 26 when his car slid off an icy road and hit a telephone pole. Now, Dimmen's granddaughter is coping not just with the loss of her father, but the sudden loss of her young son.

"It's sad," he said. "[She's] having a heck of a time. It's so close to the last one."

The Chisago County Sheriff's Office and Midwest Medical Examiner are investigating Sunday's accident, which was reported just after 4 p.m. just outside Lindstrom, about 45 minutes northeast of the Twin Cities. No one witnessed the incident.

Dimmen said Landon had wandered outside the home, where a child's size four-wheeler that his 7-year-old brother used was parked on a slope. When the toddler tried to pull the ATV off the embankment, it rolled over on top of him.

"It wasn't his to drive or anything," Dimmen said.

The ATV industry doesn't recommend that children under the age of 6 use an ATV, either as a driver or passenger, even child-sized ones. From 2003 to 2013, 13 children have been killed while riding ATVs on public roads in Minnesota. In 150 accidents reviewed by the Star Tribune, 40 percent of the riders were younger than 16 and driving on public roads.

But in Lindstrom, Dimmen said Landon never even started up the engine of the child's-size ATV before it fell on top of him.

The family rushed outside to try to revive him, doing CPR as they drove him to Osceola Medical Center in Wisconsin, the nearest hospital, where he was pronounced dead.

Landon's funeral will be held Thursday at Roberts Family Funeral Home in Forest Lake. In addition to his extended family, he is survived by his parents, Nick and Heather, and two brothers.