The National Trust says it could have done nothing to prevent the unforeseeable death of a schoolboy crushed by a branch from a tree on one of its Norfolk estates.

The National Trust says it could have done nothing to prevent the unforeseeable death of a schoolboy crushed by a branch from a tree on one of its Norfolk estates.

Daniel Mullinger, 11, had been taking part in an orienteering exercise at Felbrigg Hall, near Cromer, when a 23m-long branch fell on him and three other pupils.

The two-day inquest at the Assembly House in Norwich was told a teacher heard a loud crack, which she compared with “the creaking of a door in a horror movie”.

She shouted at the children to run but a branch fell, killing Daniel instantly and injuring fellow pupils.

Heathland School in West Bergolt, Essex, had taken 59 children to the National Trust estate during a five-day trip to the nearby Aylmerton Field Studies Centre, which it had visited annually since 2002.

The jury at the inquest was told the National Trust has a responsibility for trees at Felbrigg, and a policy of inspection and management.

The tree was in an area classed as “medium risk” and staff checked the area more frequently than National Trust guidance requirements.

Forester Richard Daplyn, who works at Felbrigg, said the area of the tree was last formally checked during a walk around the site six months before the incident and no defects were found.

However, an arboriculturalist who inspected the tree afterwards believed it was in poor condition and should have been regarded as high risk. He said the branch fall could have been down to high winds before the incident, rain and a phenomenon known as “summer branch drop”.

But another arboriculturalist, Richard Ravencroft, said the tree appeared to have good vigour and the branch fall could have been down to a problem that had built up over a number of years and which would not have been visible during inspections from the ground.

Returning a verdict of accidental death, the jury ruled that “this field trip was appropriately organised and supervised by the school and the local education authority.”

Greater Norwich coroner William Armstrong said: “Daniel died in a well-organised and carefully planned trip. He was in the conscientious care of responsible teachers and he died as a result of an unforeseen accident.

“Daniel was a special little boy, a much loved son and brother. We can only hope, as his family mourn his death, that they are comforted by the many treasured memories of a lovely little boy.”

Fellow pupil Harry Bowen, 11, who still uses a wheelchair as a result of the accident, hugged Daniel's mother, Wendy, after the verdict. Katie Farthing, 11, and Max Farley, 10, were also injured.

After the hearing, Peter Griffiths, regional director for the National Trust, said: “None of us in the National Trust can imagine how very difficult the past two days have been for Daniel's family - having to relive the tragic accident at Felbrigg last year, nor the pain and suffering that they must have experienced during the last 12 months.

“Our hearts go out to them and the parents of Harry Bowen and the two other children who were injured. We hope that the inquest this week will have helped them gain an understanding of what happened that tragic day.

“The National Trust is keenly aware of its responsibilities to minimise risks and keeps its procedures under frequent review. To that end, we note that the experts in this case have agreed that our policies and procedures were in accord with accepted industry standards, and after what the Coroner has described as a comprehensive investigation, North Norfolk District Council have stated that in their view this was an accident that was not foreseeable.”

Daniel's parents declined to comment.

Children were playing in the grounds of Felbrigg Hall last Thursday - exactly a year after a schoolboy was killed by a falling tree branch.

And the National Trust, which runs the north Norfolk stately home, urgent parents not to let the tragedy put them off

allowing children to enjoy the countryside.

A two-day inquest has just concluded that the death of 11-year-old Daniel Mullinger, during a school field study trip from Essex, was an unforeseeable accident.

Trust regional communications manager Nick Champion said there was no sign that the accident had hit the numbers of families or school parties visiting Felbrigg or other properties in the region.

Daniel's school from West Bergholt had even been back to Felbrigg this month.

“This is not something which should discourage parents from sending children on field studies.

“The Trust feels it is hugely important for youngsters to get close to nature. While we can never guarantee safety, we can minimise the risks,” he added.

Forestry staff at Felbrigg inspected trees more frequently than the minimums required by health and safety rules.

The area of the tragedy was medium risk, requiring inspection at least two yearly, but it was actually done annually - and had been looked at twice in January following storms which came soon after the regular check.

More than 1.2m people visited Trust properties in the eastern region, and it was the first fatality anyone could remember.

Watching families enjoying themselves on Thursday, Mr Champion said staff at the hall had been distressed by the tragedy, which was “everybody's worst nightmare” and would spend some time in quiet reflection during the anniversary.

A further investigation into the accident was being carried out by North Norfolk District Council on behalf of the Health and Safety Executive, he added.

A council statement said investigations showed the school trip was well organised and the woodland managed was in line with guidance, but that tree inspection was “not an exact science”.

The investigation was in its final phase and “evidence at this stage does not suggest that formal enforcement action will be taken against any of the parties involved,” said the council.