SINGAPORE - A tree in Marsiling Park that fell and killed a woman in February 2021 was infested with termites but did not show visible signs of poor health, the National Parks Board (NParks) said on Thursday.

On the first day of a coroner's inquiry into the death of Ms Loke Xiao Li, NParks' group director of streetscape Oh Cheow Sheng said the termite infestation was not detected when a visual tree assessment was last conducted in April 2020.

The termites had entered the 20m-tall Araucaria excelsa tree from beneath the ground, leaving no visible signs such as a mud trail or mound.

Nutrients and water could still flow to the tree, which had a girth of 1.3m, and its foliage did not show any symptom of poor health, Mr Oh said.

NParks inspected the tree every 24 months until June 2019, when the period was shortened to every 18 months due to more intense weather conditions such as high rainfall, he added.

"The tree was consistently recorded as being in healthy condition and excellent rigour, with no decay and no cavities," said Mr Oh.

Noting that NParks manages six million trees, Mr Oh said visual assessments are carried out regularly on trees in urban areas in alignment with international best practices laid out by the International Society of Arboriculture.

"During a visual tree assessment, a tree's crown, branches, trunk and the site conditions around the tree will be inspected in a rigorous and systematic way."

When State Coroner Adam Nakhoda asked if the NParks officers conducting such assessments were certified arborists, Mr Oh said not all of them were, as this would require them to have at least three years of working experience in arboriculture.

Mr Oh said a second, more advanced, assessment may be conducted in certain conditions, including if the visual tree assessment reveals the presence of defects that warrant further investigation.

The second level of checks, which are more rigorous and stringent, involves specialised equipment such as a high-tech drill that assesses the quality of a tree's internal wood based on the resistance met by the drill.

"However, such techniques and resources can be cost-intensive. It is not practical nor financially feasible to conduct advanced-level inspection as a blanket measure," said Mr Oh.

Representing Ms Loke's parents, who were in court, Mr Azri Imran Tan from IRB Law asked about weather conditions on Feb 18, 2021, the day of the incident.

Mr Oh said that based on his recollections, it was not raining and wind gust was moderate.

Mr Tan also asked if the age and weight of the tree could have caused it to collapse. Mr Oh said the tree was relatively young, and a healthy, living tree would have been able to sustain its own weight.

As a precautionary measure, NParks conducted visual assessments of the other Araucaria excelsa trees in the park and treated them with termiticide.

Mr Oh said: "This is a very rare situation where the tree is structurally compromised, yet did not show any external signs or symptoms... For the past 12 years, there have been only three cases in which tree failure is attributed directly to termite infestations."

The inquiry will continue on Friday.

This article was first published in The Straits Times. Permission required for reproduction.