Fairground workers have been convicted of manslaughter by gross negligence after a girl died when the bouncy castle she was playing in was swept away by the wind.

Married couple Shelby and William Thurston failed to adequately anchor the inflatable dome to the ground and monitor weather conditions to ensure it was safe for it to be in use, a court heard.

Summer Grant was trapped inside when a gust of wind blew it into the air. It travelled 300 metres down a hill and struck a tree before coming to rest.

The seven-year-old from Norwich was taken to hospital but sadly died a short time later.

Shelby Thurston, 25, and William Thurston Jnr, 28, both of Whitecross Road, Wilburton, were arrested following the incident in Harlow Town Park on March 26, 2016.

Following a thorough investigation, they were charged in June last year with manslaughter by gross negligence.

They were also charged with two counts of failing to discharge a general health and safety duty under the Health and Safety at Work Act.

The couple stood trial at Chelmsford Crown Court on April 16 and on May 9 a jury found them both guilty of all the charges.

Speaking after the hearing, senior investigating officer, Detective Chief Inspector Daniel Stoten, of the Kent and Essex Serious Crime Directorate, said: “Summer Grant was a seven-year-old girl who lost her life in the most tragic of circumstances.

“The inflatable should never have been in use in those weather conditions and the operators should never have allowed Summer to play on it.

“The Thurstons held a huge responsibility to ensure the safety of the children that used their rides. They treated this responsibility with total disregard, putting profit before safety.

“I welcome the convictions in this case, however this is a tragedy for everyone involved.

“Summer Grant was a beautiful little girl with a beaming smile and a caring nature. She will never be forgotten.

“Summer’s parents Cara and Lee, her sister Lily and her wider family have suffered an unspeakable loss.

“They have displayed utter dignity throughout the last two years and during the court process. They have my complete respect for the strength and courage they have shown.”

Witnesses told the court it had been raining and windy on the day of the incident.

A yellow weather wind warning was in place and the weather forecast for the coming weekend was stormy, with Storm Katie expected to arrive on March 28.

The Thurstons were running a number of rides at the funfair, including three inflatables – a large slide, a smaller slide and the Circus Super Dome that was involved in the incident.

They opened their rides at about 2.15pm but at 3.30pm William Thurston decided to deflate the large slide due to forecast weather conditions.

While the larger slide was being deflated, Summer was on the dome when it lifted into the air and blew away.

The Thurstons told the court they had regularly checked Met Office weather updates on the day and had seen the wind was due to pick up in a few hours, so agreed to deflate the big slide first due to the rain. They claimed it was not windy and a sudden gust blew the dome away.

A meteorologist confirmed weather warnings were in place that day for the area covering the park and wind speeds and gusts had increased throughout the day, reaching as high as 35mph to 45mph during the late afternoon.

Sentencing has been adjourned until a date yet to be set.