SINGAPORE - A 40m-tall Tembusu tree fell at the Singapore Botanic Gardens (SBG) on Saturday (Feb 11) afternoon, killing one and injuring four people.

Police said that a 38-year-old female Indian national died. Her husband, a 39-year-old French national, and their two children, aged one, were injured. A 26-year-old female Singaporean was also injured in the incident.

The National Parks Board (NParks) said that the tree was more than 270 years old and predated the establishment of the Gardens. It fell and brought down surrounding palm trees.

It was last inspected in September 2016 and was found to be healthy, said NParks. It is investigating what caused the tree to fall.

Those hurt in the incident, including the two children, were taken to the National University Hospital in three ambulances, said the Singapore Civil Defence Force (SCDF).

The Tembusu tree, which had a 6.5m girth, was uprooted at 4.25pm at the edge of Palm Valley near the Shaw Foundation Symphony Stage.

"We are sad that there was one fatality and four other injured persons. Our priority now is to accord assistance to the families of the deceased and the injured," said Mr Kenneth Er, chief executive officer of NParks, in a statement on Saturday evening.

"As an SBG Heritage tree, it was inspected twice a year, which is of a higher frequency than other trees in the Gardens. The tree was also protected by a lightning conductor and fenced off to prevent compaction of its root zone by visitors. Leaf litter is routinely applied to the root zone to encourage healthy root growth," he added.

A concert scheduled for the evening has been cancelled. The concert, called "Canada 150: Celebrating Diversity through Music and Film", was supposed to take place at the stage from 5pm to 7pm.

All programmes at the Singapore Botanic Gardens on Sunday (Feb 12) have been cancelled.

Police and the SCDF were at the scene when The Straits Times went there around 5.30pm.

NParks told The Straits Times that it is focusing on clearing up the site.

Artist Tina Fung, 34, said: "I was walking towards the event at the stage. I didn't hear it (fall). Two guys had scratches on their legs, and there was a lady they were trying to resuscitate. It looked pretty serious."

"Some people (members of public) were trying to rush to help, but they were cordoning off the space," she said. Ms Fung is the artist behind the Canada 150 structure, which is supposed to be unveiled today.

Manager Mr Zhou, 49, arrived at the site several minutes after the tree fell. He said that the injured woman looked to be Indian and that rescue efforts were "pretty fast."

On Saturday (Feb 11), Deputy Prime Minister Tharman Shanmugaratnam expressed his sympathies to the family of the person who was killed, and stated that investigations are ongoing as to why the tree fell.

In a Facebook statement, police advised members of the public to stay away from the site to facilitate the rescue work by the Singapore Police Force and the SCDF.

Dr Shawn Lum, a botany expert from Nanyang Technological University's Asian School of the Environment, said he was surprised and sad to hear about the incident.

A possible, but unlikely, reason for the tree uprooting could be that rot or a fungal infection had occurred in the root area of the tree, causing it to weaken and eventually fail. However, this is not a common occurrence in Tembusu trees, said Dr Lum, who is also president of the Nature Society (Singapore).

The recent heavy rains and gusty winds experienced on Saturday could also have been a factor, he said. "The Tembusu that fell is on a slope, although not a very steep one. But after the recent heavy rains and the very gusty winds on Saturday and on Friday, it could be that the slope gave way first rather than the tree itself."

The reason for the tree's fall still remains to be seen, said Dr Lum, but it is something that cannot be anticipated.

Tembusu trees, which thrive even on very poor soils, are commonly planted in parks and along roadsides. At least 10 such trees in places like the Singapore Botanic Gardens, St John's Island and Sentosa have been designated Heritage Trees.

Native to Singapore, the evergreen tree with low-lying branches can reach heights of up to 40m. It can live more than 100 years.

The most famous Tembusu is the one at Lawn E of Botanic Gardens near the Swan Lake. The tree, which is more than 200 years old, is featured on Singapore's $5 note. It was fenced up in 2013 to prevent visitors from treading around it and affecting the growth of its roots.

Here is the text of the National Parks Board statement in full:

11 February 2017, Singapore - A 40m tall Tembusu Heritage Tree of 6.5m girth was uprooted at 4.25pm today at the edge of Palm Valley in the Singapore Botanic Gardens. This tree was more than 270 years old and predated the establishment of the Gardens. It fell and brought down surrounding palm trees.

We are investigating the cause of the tree fall. It was last inspected in September 2016 and was found to be healthy.

As an SBG Heritage tree, it was inspected twice a year, which is of a higher frequency than other trees in the Gardens. The tree was also protected by a lightning conductor and fenced off to prevent compaction of its root zone by visitors. Leaf litter is routinely applied to the root zone to encourage healthy root growth.

We are sad that there was one fatality and four other injured persons.

Our priority now is to accord assistance to the families of the deceased and the injured.

Mr Kenneth Er
Chief Executive Officer
National Parks Board