A 4-year-old boy fell two stories out of a screened window at the family's Waconia home, landed on a back yard concrete patio and was critically hurt, authorities said.

Emergency personnel arrived to find the boy, Quinn Ruhl Larson, unresponsive but breathing after the fall of 12 feet about 12:20 p.m. Sunday at the house in the 1300 block of Creekside Circle, according to the Sheriff's Office.

Quinn, with a bump on his forehead, was at Hennepin County Medical Center in critical condition Monday afternoon, the Sheriff's Office added.

The fall has been ruled an accident, the Sheriff's Office said.

According to the investigation:

The family had recently moved into the home and were upstairs assembling furniture in the bedrooms when the boy went to the back of the main floor, where he likely was climbing on a sofa and looking out the window.

It was then that the screen gave way and the child tumbled out. The parents told the Sheriff's Office that the windows were open and screens were in place at the time.

A neighbor who was outside heard the incident and found the boy on the patio outside a basement walkout door, notified the parents and called 911 for assistance. A screen was found near the boy after he fell.

"Windows open just five inches can create a hazard for young children," Sheriff Jim Olson said. "And window screens are designed to keep insects out but offer very little protection to keep kids in."

Paul Walsh • 612-673-4482