The girl went into cardiac arrest as she was pinned under the branch during lunch time at Pitt Town Public School and the NSW government has started a tree inspection program at schools in response to the tragedy.

In the ACT, arborist contractors hired by the Territory and Municipal Services Directorate undertake tree audits of public schools every 12 months. A spokeswoman from the Education and Training Directorate said this program was being expanded to include childcare centres.

''Principals have an active role in maintaining their school sites. ETD then works with schools to action recommended works accordingly,'' she said.

Australian National University forestry expert Cris Brack said an annual check was a good outcome.

''Annual checks will pick up slow deterioration, but they won't pick up sudden failures [in the] 600,000-plus trees in Canberra, and you can't do invasive checks, so an annual health check is pretty good and I can't see how you could do much more,'' Dr Brack said.

He said sudden failures were unavoidable even with constant monitoring.

''Sydney was a sudden failure - there was no outward sign of deterioration, slowly, in terms of stresses on the tree. They can literally just snap because of internal stresses.''

In 2001, a seven-year-old boy was killed at Brindabella Christian College in Canberra after falling from a broken tree branch that then crushed him.

Kristian Graeme Blackman was in year two and his mother Karen Blackman said the death of eight year-old Bridget Wright at Pitt Town brought it all back. She did not want to comment on the recent tragedy but said tree safety should be monitored in schools.

The ACT has the largest urban forest per square metre in Australia with 730,000 street trees audited and maintained by TAMS.