A seven-year-old girl has died after the bouncy castle she was playing on was blown away in strong winds.
A 24-year-old woman and a 27-year-old man have been arrested on suspicion of manslaughter by gross negligence.
Paramedics were called to Harlow Town Park in Essex shortly after 16:00 GMT on Saturday, where the third day of an event organised by Thurston fun fairs was taking place. The girl, from Norwich, died in hospital.
It is believed the dome-shaped inflatable carrying the girl blew over a number of trailers and caravans in the park and landed down a hill. Ray Smith, a representative of the Showmans Guild of Great Britain, said: “It was a sudden gust. Had it been a consistent wind they would have closed down all the inflatables.”
East of England Ambulance Service said the girl had suffered serious injuries when the inflatable was blown “some distance”. She was treated by ambulance crews and the Essex and Herts Air Ambulance before being taken to the Princess Alexandra Hospital in Harlow.
A spokesman for the ambulance service said: “Our thoughts are with the friends and family involved on this sad day.”
Asked about how the inflatables were set up, Mr Smith said: “I know the (Thurston) family and I am very confident they had staked it out properly.
“Obviously there is a full investigation to be held into how this could have happened and to make sure it can never ever happen again.”
The arrested pair, from Cambridgeshire, are understood to be from the family-run bouncy castle firm.
Floral tributes have been left at the gates of the park, where a section remains cordoned off by police.
Among them is an Easter basket, while a card on a bunch of flowers reads: “God has taken a beautiful girl for his angel. RIP Princess.”
Det Insp Daniel Stoten, of the Kent and Essex serious crime directorate, said: “This is a very tragic incident. The weather will certainly make up part of this investigation – whether the weather was a factor and whether or not it was appropriate for the ride to be running.
“It will be a complex and thorough investigation – I do not anticipate this to be a quick inquiry, it will be a lengthy investigation.
“We are trying to establish the circumstances surrounding how the girl came to be injured and I urge anyone who was at the event and witnessed the incident to contact me.”
Officers urged anyone who captured the incident on camera to get in touch. The Health and Safety Executive said it was assisting police with the investigation.
Last year a bouncy castle collapsed while children were playing on it during a fair in the park.
Harlow Council officers visited the site following the incident last May and suggested a number of health and safety improvements, including better stewarding of the event. It was reported at the time that three children were treated by paramedics when the inflatable castle collapsed on them.
After news of Saturday’s tragedy broke, Conservative MP for Harlow Robert Halfon tweeted: “My thoughts and heart go to family.”
He added in a statement that he would be asking for an “urgent inquiry” and to consider whether bouncy castles “should be banned from Harlow town fairs, until we can be sure that they are completely safe, so such a horrific tragedy never happens again”.
Jon Clempner, leader of Harlow Council, said: “Harlow is a town in shock following this tragic incident yesterday. I can’t imagine the heartache of the parents and family of the little girl who has died, and my thoughts are with them.”