SINGAPORE — The 40m-tall Tembusu heritage tree that toppled and killed a woman at the Singapore Botanic Gardens in February this year had suffered from decay that started from its roots but had not been visible to those inspecting the tree.
During the Coroner’s Inquiry into the death of 38-year-old Indian national Radhika Angara on Tuesday (July 18), Mr Derek Yap, the arborist who prepared the report after the incident, said that about 70 per cent of the trunk at its 2m point – measured from the ground level – was decayed and this amount of decay would have affected the structural integrity of the tree.
These would reduce the anchorage and structural stability of the whole tree and was what contributed to the failure of the tree, he added. Mr Yap was the second of the State Counsel’s three witnesses to take the stand in the one-day hearing. He currently does private consultancy work at private firm Camphora.
Noting that the roots of the tree appeared to have been cut and later decayed, Mr Yap also agreed with State Coroner Marvin Bay that there was a possibility that the decay had festered from 1859 – the last time the tree’s roots were cut when the Singapore Botanic Gardens was founded.
But he added the decay could not be seen by inspectors as it was below the soil level.
When asked by State Counsel Kumaresan Gohulabalan if the National Parks Board (NParks) could have predicted that the tree could topple over, Mr Yap said there was no external signs to show decay in the trunk and inspectors also could not do an assessment of the tree below soil level.
“The inspector would not have any signs to tell him that tree had issues that would need additional mitigating measures. My opinion is that the tree failure was unpredictable,” he added.
Mr Yap also described the mechanics behind the toppling of the tree on Feb 11 this year. He noted that there was most likely a localised increase in wind speed that day and together with the “asymmetrical canopy” of the tree, the crown had to bear an increased load. This load was then passed down through the trunk and into the root plate. The load was also heavy enough to cause cracks in the trunk and caused the tree to topple.
The hearing was also attended by Ms Angara’s next-of-kins, her sister, father and her husband Mr Jerome Rouch-Sirech (seen below). They were represented by lawyer Chelva Retnam Rajah.
During the hearing, the deceased’s sister had asked if there was a differential treatment of older and younger trees. The Tembusu tree that toppled over was more than 270 years old and given a clean bill of health during its last inspection in September last year.
In response, Mr Yap said while old trees with defects will get more attention, old trees without defects will not be treated any differently from normal, healthy trees.
For a heritage tree, inspectors will first do a visual assessment to check if there are external signs of stress, such as decay. And the focus will mainly be on maintenance for these trees, such as taking out dead branches and trimming it, he said.
The hearing continues later this afternoon.