Three Whitby, North Yorkshire, children were playing on a bouncy castle when it was caught up in high winds, took off and hit a telegraph pole.
The children were on the castle as friends and relatives celebrated a double christening at The White House Hotel.
Eyewitnesses heard screams and saw children lying on the floor as the drama unfolded on Sunday afternoon.
“I was watching the grand prix and heard loads of kids screaming,” one said. “I looked up and there was the bouncy castle in mid-air.
“I saw kids on the floor – it was a bit of a shock.
“The air ambulance struggled to land in that wind and they closed the road off so you couldn’t get near.
“They struggled with the bouncy castle first thing this morning with it being so windy. It was very lucky where it landed, with the wind coming this way, that the telegraph pole is where it is.”
The Whitby Gazette reports that the seven-year-old boy suffered a broken rib, a punctured lung, a broken femur and also broke his arm in two places.
His nine-year-old brother was taken to Scarborough Hospital with a broken knee and a seven year old girl suffered head injuries and concussion and was also taken to hospital.
Police said they were no longer involved in an investigation but the Scarborough Council would be conducting its own investigation.
“In respect of that it is innappropriate for us to comment further while the children are still in hospital. Our best wishes go out to them.”