Sunday, February 19, 2017

Tembusu Tree Fell in Singapore Botanic Garden, Killing One

On Feb 11 (Sat) at about 4.30pm, a Tembusu tree 40m tall with a 6.5m girth fell in the Singapore Botanic Gardens, killing a woman who was with her husband and two children, and a woman who was with her friends was injured. The Tembusu tree was estimated to be 270 year old and had been on the site of the Botanic Gardens when it was established in 1859. The site was managed by the National Parks Board (NParks).

 The fallen Tembusu tree being assessed by investigators. (Photo credit: Today Online)

 
The Tembusu tree in Palm Valley of Singapore Botanic Gardens, taken on May 2014. (Photo credit: Google Streetview)

Photos of the Tembusu tree, which was a Heritage Tree, was taken down from the NParks website after the incident. The unique ID of the tree is HT 2001-34.

Screenshot of cache of the National Parks Board website, as it appeared on 28 Jan 2017. Note the "Last updated on 11 May 2016" at the bottom.

Screenshot of cache of the National Parks Board website, as it appeared on 28 Jan 2017. Note the "Last updated on 11 May 2016" at the bottom.

Screenshot of the the National Parks Board website captured on 12 Feb 2017. Note the "Last updated on 12 Februrary 2017" at the bottom.

Mr Simon Leong, an arborist of Urban Forester said on evening news that the soil may be satured after heavy rain, and stability of the tree will be "compromised". Continuing, he mentioned that after a "slight movement of the soil condition", the wind load from the tree may be "too big" and that is why it "can come down by itself". He added that "root support system" could help stabilise trees. [source: https://www.youtube.com/watch?v=S8R6lBIwZ_Q]

Screenshot of the "root support system" that Simon Leong mentioned in that interview.

Mr Lahiru Wijedasa, a former senior arborist at Singapore Botanic Gardens said that the tree was "unlikely to have fallen due to the lack of space". And that recent winds and rain could cause a "compromised" tree to be uprooted. [source: http://news.asiaone.com/news/singapore/botanic-gardens-tragedy-not-likely-tree-fell-owing-lack-space]

Mr Ng Tze Peng, an arborist of TP Arbo Care suggested that the investigators would have to study the whole tree, especially its root system, and environment and weather at the time of the incident. [source: http://www.channelnewsasia.com/news/singapore/botanic-gardens-tembusu-tree-that-fell-last-inspected-in/3511820.html]

Mr Andy Tan, managing director of Tan Huan Arboriculture Services opined that the probable cause of the tree failure was attributed to "water-logging due to recent heavy rains, resulting in surrounding soil to loosen and roots to rot". He added that "strong winds... could have further exacerbated the problem".
[source: http://www.channelnewsasia.com/news/singapore/botanic-gardens-tembusu-tree-that-fell-last-inspected-in/3511820.html]

A few days after the incident, on 13 Feb (Mon), a Rain tree on the site of student apartments [Scholars Residence] at Yuan Ching Road fell and injured a woman. The site was managed by the Singapore Land Authority (SLA). [source: http://www.channelnewsasia.com/news/singapore/woman-in-icu-after-getting-hit-by-falling-tree-at-yuan-ching/3515594.html]
A manager of the student apartments said that "this was the second time a  tree had fallen there". An earlier incident happened "last year [2016] but no one was injured". [source: http://www.straitstimes.com/singapore/woman-seriously-injured-by-falling-tree-in-carpark]

The tree fell onto the door of a lorry and on a woman. (Photo credit: ST Reader via ST)