Her French husband, Mr Jerome Rouch-Sirech, 39, and their two children, one-year-old twins, were also injured in the incident.
Ms Angara, an Indian national, moved to Singapore in January 2013 when she joined global social and mobile payment platform Fastacash as its chief marketing and strategy officer.
She was previously vice-president of marketing at Myntra Designs in Bangalore, India.
Ms Angara, who studied at the University of Pennsylvania and Ithaca College in the United States, had also held positions at France-based company electronic payment company Ingenico and international food company General Mills.
She left Fastacash last year and joined Mastercard as its regional digital marketing head for Asia Pacific.
In a message sent to The Straits Times, Fastacash CEO Mark Carter said: "Radhika was a pivotal member of the Fastacash management team and an inspirational leader who garnered huge respect from all whom knew her.
"Radhika was always there to support colleagues through the Fastacash journey and will be deeply missed. Our condolences and deepest sympathies go to her family at this sad time."
The Straits Times understands that Mr Rouch-Sirech was discharged from National University Hospital on Saturday night. He heads retail at Puma South East Asia, according to his Linkedin profile.
The family's home is believed to be at a three-room condominium in the central part of Singapore.
A 26-year-old female Singaporean was also injured in the incident that took place at least 50m away from the Shaw Foundation Symphony Stage.
The Straits Times understands that her name is Ms Tay Pei Lei and that she has been discharged too from NUH.
National Parks Board (NParks), which manages the Gardens, said it is investigating the reason the tree fell.
In an update on Sunday afternoon (Feb 12), NParks assured the public that it shares concerns about the safety of its trees in the Singapore Botanic Gardens, especially in view of the recent spate of intense weather conditions.
"We have completed a detailed check of all the trees in Palm Valley and they are safe. We are also in the midst of conducting more checks for trees in the vicinity of the Palm Valley (such as the Rainforest) and all the Heritage Trees in the Gardens," said Dr Leong Chee Chiew, Commissioner of Parks and Recreation at NParks, in a statement.
Palm Valley, which was the site of the crash, remains closed to public access while clearance operations and investigations are ongoing. The rest of the Gardens remains open and is safe for the public to visit.
The Tembusu tree that fell was a heritage tree and inspected twice a year, which is of a higher frequency than other trees in the Gardens, Dr Leong added.
"This includes checks on the root collar, anchoring roots, crown, trunk and signs of soil movement. The tree was also protected by a lightning conductor and fenced off to prevent compaction of its root zone by visitors," he said.
He added that leaf litter is routinely applied to the root zone to encourage healthy root growth. The tree was last inspected in September 2016 and was found to be healthy.
Dr Leong said it has increased the frequency of inspections of trees along expressways and major roads, and has taken steps to improve the general health of its trees, for example, such as pruning prior to periods of more severe weather conditions.
"Going forward, we are already developing modelling techniques to better understand the structural behaviour of trees under varying environmental conditions like rain, wind and soil," he added.
He also urged the public not to speculate on the cause of the tree fall and allow the due process to take its course, as it is still investigating the incident.
Its priority now is to provide assistance to the families of the deceased and the injured, he said.
Correction note: An earlier version of the story said that Ms Angara was a marketing and strategy officer with Fastacash. Her last-held job should be a regional digital marketing head for Asia Pacific with Mastercard. We are sorry for the error.
This article was first published on Feb 12, 2017.
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