Police released the name of a 5-year-old Layton boy killed Saturday night during a family hay ride near Farmington.

Kai Jorgensen was run over by the rear tires of a flatbed trailer when his mother lowered him to the ground while it was still moving, said Davis County sheriff's Capt. Kenneth Payne.

"A whole bunch of other kids were jumping off, and he wanted to get down," Payne said. "She was trying to lower him to the ground ... and he got pulled under the wheels."

He was killed instantly.

The ride is a family tradition at the Farmington Bay Waterfowl Management Area, located near 1325 W. and 925 South near the Great Salt Lake. More than 30 relatives of the boy were on the trailer as it slowed to a stop on the way back from the bird refuge about 10 p.m.

No criminal charges will be filed. "We're just treating it as an unfortunate accident," Payne said. "The family has suffered enough."

A woman who answered the phone at the Jorgensen house and identified herself as the boy's grandmother said the family had no comment.