Last updated at 4:48 p.m. ET
A homemade balloon aircraft floated away from a yard in Colorado after a 6-year-old boy was seen climbing inside, setting off a frantic scramble by the military and law enforcement before the balloon slowly touched without the boy inside.
A sheriff's official later said the boy climbed into a box attached to the balloon, but the basket not found at crash.
It's not clear whether the boy fell out of the balloon or was never actually inside the craft. Sheriff's officials said from the beginning that he was in the balloon, and authorities feverishly searched for any sign of the child on the ground, including in the neighborhood where he lives.
The bizarre scene played out live on television as the balloon rotated slowly in the wind, tipping precariously at times before gliding to the ground after more than two hours in the air.
Cathy Davis of the Larimer County Sheriff's Department told reporters the balloon was owned by the boy's parents, Richard and Mayumi Heene, and tethered behind the family's home. She said two sons were playing outside when the older boy saw the younger one, identified as Falcon, go into a compartment at the bottom of the balloon and fly away.
Richard Heene is a storm chaser and scientist. He and his wife twice appeared on the ABC show "Wife Swap," according to the network.
Davis said the family was in contact with experts to provide details on the craft, including what it's made of and what might happen when it reached the ground.
In a 2007 interview with The Denver Post, Richard Heene described becoming a storm chaser after a tornado ripped off a roof where he was working as a contractor and said he once flew a place around Hurricane Wilma's perimeter in 2005.
Pursuing bad weather was a family activity with the children coming along as the father sought evidence to prove his theory that rotating storms create their own magnetic fields.
Although Richard said he has no specialized training, they had a computer tracking system in their car and a special motorcycle.
Local reports say Richard Heene's web site is thesciencedetective.com.
The Colorado Army National Guard sent an OH-58 Kiowa helicopter and was preparing to send a Black Hawk UH-60 to try to rescue the boy, possibly by lowering someone to the balloon. They also were working with pilots of ultralight aircraft on the possibility of putting weights on the homemade craft to weigh it down.
But the balloon landed on its own in a dirt field. Sheriff's deputies secured it to keep it in place, even tossing shovelfuls of dirt on one edge.
Northbound departures at Denver International Airport were shut down as a precaution to prevent against a possible collision between the balloon and an airliner, said Lyle Burrington, an air traffic controller at the Federal Aviation Administration's radar center in Longmont, Colo.
An FAA source told CBS station KCNC pilots flying into and out of DIA were being told to watch out for the aircraft.
It helped that the day was clear, enabling pilots to see the balloon well, he said.
Federal Aviation Administration spokeswoman Laura Brown said the agency tracked the balloon through reports from pilots.
"We were sitting eating, out looking where they normally shoot off hot air balloons. My husband said he saw something. It went over our rooftop. Then we saw the big round balloonish thing, it was spinning," said neighbor Lisa Eklund.
"By the time I saw it, it traveled pretty fast," she said.
The story gripped the television news networks, which set aside other programming to follow the balloon and speculate on the safety of the boy.
"It's got everybody freaked out," said Fox News Channel's Shepard Smith, "and why wouldn't it?"