The lunch bell had just rung at Pitt Town Public School and the students of class 4/5c were filtering out into the playground, clutching their sandwiches and drink bottles.

Bridget Wright, a bright, healthy eight-year-old with a passion for reading and taekwondo, separated from the group and walked towards the toilets - a path that took her beneath the school's 90-year-old forest red gum.

As Bridget passed under the tree there was a sudden, loud crack. Without any warning or the slightest gust of wind, a seven-metre-long branch, 13 centimetres in diameter, fell from a height of six metres and struck the little girl, two other students and a teacher standing below.

The little girl suffered serious head and chest injuries from which she never recovered. Despite the best efforts of teachers, paramedics and staff at Westmead Hospital she passed away. The time and date of death was 2pm on February 23, 2014.

It was a terrible accident, but the NSW Coroner's Court heard on Monday that the school may have been warned about the tree and the specific branch four months earlier.

Arborist Nathan Stokes told the inquest into Bridget's death that when he came to Pitt Town Public School to provide a quote for unrelated tree removal work in October 2013, principal Michael Miller asked him to examine the forest red gum.

"I just pointed the branch out - didn't say it was dangerous but did say it should come out," Mr Stokes, of Ultimate Arbor Solutions, told the inquest.

"There was a lot of weight at the end of the branch, which puts a lot of pressure at the junction.

"I told Michael that the branch should have been removed for the safety of the students."

But Mr Miller had a different recollection of the conversation.

He told the inquest that while Mr Stokes had said the tree should probably be removed, he had given no indication that it provided a safety risk to students.

"At the end of that conversation I had no inkling or indication that there was a danger from that branch," Mr Miller said.

"Because of the location - close to the toilets, the canteen, on the way to the oval - I would have required the work to be done.

"My understanding was that it needed to be done but it wasn't urgent."

Mr Miller conceded that he had then "overlooked" having the tree pruned or removed.

The inquest heard that on a number of occasions Mr Miller had placed cones or chairs around the perimeter of the tree as a warning to students not to walk directly underneath it.

The inquest also heard that an expert aerial examination of the tree following Bridget's death found that the branch fell because it was unhealthy and had "significant problems".

"There was extensive fungal growth around the point from which the branch broke," counsel assisting the inquest Jake Harris said.

"There was also a three-metre cavity inside the trunk of the tree ... containing a large beehive.

"The defects weren't obvious from the ground but there was enough visible factors to warrant a visible inspection."

Despite the age of the tree, a number of buildings had been built in its immediate vicinity in the years leading up to the tragedy, including a demountable classroom that had been built three years earlier.

The inquest heard that, at the time of the incident, departmental guidelines for the maintenance of dangerous trees had been inadequate, with principals given little advice about what to do if they had a dangerous tree at their school.

Since Bridget's death the NSW Department of Education has spent $32 million on the removal of 9000 trees from school playgrounds and introduced mandatory annual tree checks.

In his closing submissions, Mr Harris said these measures were adequate to protect students.

He also said Mr Miller could not be criticised for his actions, as it appeared he had not been told the tree was dangerous, and that he would likely have acted if he had received this advice.

Coroner Helen Berry will hand down her findings in coming weeks.