Detached bungalow leaves residential street by air, last seen heading south-west.

A single-storey house on a redevelopment site in the American Midwest departed its plot by air on Tuesday morning, rising over the neighbouring construction hoardings and travelling south-west before passing out of sight. The property, owned by Ernest Vallow, 78, a retired seller of mobile inflatables, had been the last occupied building on a street otherwise cleared for a commercial scheme.

Mr Vallow was due at Fernleigh Court, a residential care complex on the edge of town, at 9am that day. A driver sent to collect him told police he arrived to find the front garden empty apart from a rectangular impression in the grass and some severed service pipes. "There were a lot of colours in the sky," he said. "I did think it was a bit early in the year for that."

Police estimate that between nine and ten thousand balloons were involved, a figure a spokesman described as "arrived at by a colleague who counted a small area and multiplied outward, so treat it as broadly indicative." A recovery co-ordinator with the county highways department confirmed that no offence had been identified. "There is nothing in the ordinance about a dwelling being moved by the occupier," he said. "It anticipates lorries. It does not anticipate this."

A nine-year-old from a neighbouring street, engaged at the time in collecting signatures towards a Junior Countryside Merit award, has not been seen since and is understood by neighbours to have been standing on the porch when the house left. His mother told reporters she was "not overly concerned yet", adding that the boy had packed sandwiches. A stray dog that had been loitering near the site for some weeks is also unaccounted for.

Neighbours described Mr Vallow as quiet since the death of his wife Marian, and said he had kept a glass jar on the mantelpiece with a phrase written on the side about getting on with things while there was still time. One recalled him mentioning a waterfall on a plateau in South America "the way other men talk about a caravan in Wales". The couple are believed never to have travelled.

Aviation officials have logged the property as an uncontrolled slow-moving object and asked that anyone sighting it not attempt to bring it down. "It is a house," a spokeswoman said. "It is behaving impeccably." A separate inquiry, unrelated, remains open into the disappearance of the explorer Hollis Crane, whose airship was last logged over the same region some decades ago.