(CNN) -- A balloon that was set adrift Thursday by a 6-year-old boy from his parents' Fort Collins, Colorado, home was empty when it landed, but authorities said they were searching for the boy on the ground.
"At this point, we are thinking that he did not fall out of the balloon and is somewhere on the ground, and we are searching the neighborhood," said Larimer County Sheriff's Office spokeswoman Eloise Campanella.
"The basket itself was not breached. It does not look like he fell out of it -- but again this is all conjecture," she said. "I'm very confident we will find him. I think it's a matter of him being a little scared ... maybe he's not ready to be found."
The boy was identified as Falcon Heene.
Falcon's parents, science enthusiasts Richard and Mayumi Heene, were featured on the 100th episode of ABC's prime-time program "Wife Swap" in March 2009, ABC said.
According to the network's Web site, the Heene family "devote(s) their time to scientific experiments that include looking for extraterrestrials and building a research-gathering flying saucer to send into the eye of the storm."
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