NParks disputes arborists’ diagnosis on tembusu tree in fatal incident

NParks disputes arborists’ diagnosis on tembusu tree in fatal incident
NG SIQI KELLY Today Online 31 Aug 17;

SINGAPORE — The Botanic Gardens tembusu tree that toppled and killed a woman in February was found to have a 1.5m long “cavity” during an inspection last September, but this was deemed a misdiagnosis, said a National Parks Board representative Wednesday (Aug 30).

At the Coroner’s Inquiry into Radhika Angara’s death, NParks deputy director Elango Velautham said a cavity in the tree trunk could suggest decay, which would mean an “intrusion into (the) structural integrity” of the tree. But on this count, the inspection report had “wrongly perceived” a natural protrusion called a flute to be a cavity, he said.

Marking a twist in the inquest, Mr Velautham’s testimony contrasted with what two independent arborists had testified last month.

According to him, the tree’s roots showed it was in good health. Its root collar was well-formed and expanded outwards to form buttress roots. There was nothing to suggest any weakness, said Mr Velautham, who specialises in arboriculture and conservation.

The independent arborists had said the tree, which was more than 270 years old, had decaying roots but no visible signs that warranted more intensive checks. They said the weather conditions before, and on the day of the incident, could also have contributed to the 40m tree toppling.

In the hearing in July, arborist Derek Yap had testified that about 70 per cent of the tree trunk at its 2m point (measured from ground level) was decayed. This could have affected the tree’s structural integrity, said the private consultant with environmental impact assessment firm Camphora.

After the “cavity” — which was 1.5m long, 0.2m deep and 0.3m wide — was identified, Mr Velautham said further checks determined it to be a “flute”, a natural protrusion and a form of protection for some trees. The inspection last September was the most recent before the fatal accident, and a report in September 2015 had not identified any defect, he said.

“A cavity of that length, depth and height could not have happened over a year,” he said.

Angara’s father, Mr Krishna Angara, was in court and questioned why the initial red flag had not warranted more sophisticated investigation using diagnostic tools, instead of “(getting) another certified arborist to say it is not a cavity”.

Lawyer Chelva Rajah, who is acting for the family, questioned the absence of documentary proof showing how the misdiagnosis was determined. The initial report had identified what appeared to be a serious defect in the tree, he noted.

In response, Mr Velautham said NParks arborists had written an “internal statement” after following up on the September 2016 report. They noted the flute was “wrongly perceived” as a cavity. But the document was not produced in court Wednesday.

The court also heard that “trees of interest” such as the tembusu tree are inspected twice a year, double what international standards require. Such trees include large trees, trees in carparks and by the road, and those in areas “highly frequented” by people.

Angara, a regional digital marketing head for Asia-Pacific at MasterCard, was at an outdoor concert near the gardens’ Shaw Foundation Symphony Stage on Feb 11 when the tree toppled. The 38-year-old Indian national died from traumatic asphyxia with broken ribs at 5.17pm that day, about an hour after the tree fell on her. Her French husband Jerome Rouch-Sirech and their one-year-old twins were also injured.

Mr Rouch-Sirech and Angara’s parents and sister were in court Wednesday. The inquiry will continue on Sept 21.

Tembusu tree accident: Botanic Gardens official says there was 'no decay, no cavity'
Vanessa Paige Chelvan Channel NewsAsia 30 Aug 17;

SINGAPORE: The Tembusu tree that uprooted in February, killing one, had passed its last inspection in September 2016, though an arborist had raised concerns the 40m tall, 270-year-old tree might have a cavity.

But a second inspection by the Singapore Botanic Gardens’ deputy director Elango Velautham and his team of arborists assessed the suspected cavity to be a flute, an inquiry into the death of 38-year-old Radhika Angara was told. Ms Angara was pinned under the heritage tree when it toppled on Feb 11.

She was with her French husband and their one-year-old twins at the gardens near the Shaw Foundation Symphony stage to attend an outdoor concert when the accident happened. Ms Angara was killed when the tree fell on her, while four others, including her husband and children, were injured.

There was “no decay, no cavity”, Mr Velautham said on Wednesday (Aug 30). An inspection after the Tembusu had fallen confirmed that the suspected cavity was, in fact, a flute 1.5m in length, 0.2m deep and with a width of 0.3m, the inquiry heard.

He described a flute to be a “protruding structure” on a tree’s trunk formed in response to “environmental exertions” to the tree.

However, two independent arborists who testified before the inquiry last month agreed that the tree’s roots were in decay, though there were no visible signs that warranted more intensive checks. They also said weather conditions in the days before could have contributed to the toppling of the tree.

The Tembusu is “a very slow growing tree”, Mr Velautham said, and any decay would “take a very long time to … destabilise a tree”. Tembusu wood is tough and durable, and this tree in particular had outlasted two World Wars. The structural integrity of the tree could not have been compromised in the short time since its last inspection, Mr Velautham said.

The Tembusu tree in question was inspected twice a year, as are other large heritage trees, trees in carparks, and trees in areas where “the occupancy rate is high”, he said. The fact that the tree was over 200 years old did not make it “high risk” or affect the inspection schedule, the inquiry heard.

Inspections are “age independent”, and carried out “based on the assumption that all trees, big and small, pose risk”, he added.

The inquiry will resume at a later date, giving Mr Velautham time to produce certain inspection records at the request of Mr Chelva Retnam Rajah, who is representing Ms Angara’s family.
Source: CNA/jp