The legacy of prominent business leader Kwek Leng Joo will endure, said Prime Minister Lee Hsien Loong in his condolence letter to the family.
In a letter addressed to Mr Kwek's widow Alice, Mr Lee said: "Leng Joo left us suddenly when he had so much more to give. Singapore has lost a champion of the environment, leader of corporate social responsibility, and a fine photographer with a big heart."
Mr Lee said he last met Mr Kwek only two weeks ago at his art exhibition at the National Museum of Singapore. He added that Mr Kwek contributed photographs used in the bid to have the Botanic Gardens declared a Unesco World Heritage Site.
"I am glad that he lived to see the success of the bid. We could not have done it without him... Leng Joo's legacy will endure."
The City Developments (CDL) deputy chairman, aged 62, died in his sleep after suffering a heart attack on Monday.
Mr Lee and his wife Ho Ching paid their respects yesterday evening, CDL said. Deputy Prime Minister and Coordinating Minister for National Security Teo Chee Hean and British High Commissioner to Singapore Scott Wightman visited in the afternoon.
President Tony Tan Keng Yam said he was deeply saddened to hear of the news. In a Facebook post yesterday, Dr Tan said Mr Kwek made lifelong contributions to Singapore's economic, environmental and social development.
"It was only last month that I had the pleasure of presenting Leng Joo with the President's Award for the Environment, for his dedication and contributions to the pursuit of environmental excellence."
More tributes poured in from business and civic groups, as well as political leaders.
Communications and Information Minister Yaacob Ibrahim and Culture, Community and Youth Minister Grace Fu took to Facebook to remember Mr Kwek and his philanthropic works.
Dr Yaacob recalled opening the world's first green library for children with Mr Kwek at the Central Public Library in 2013.
Ms Fu singled out Mr Kwek's contributions to Singapore's cultural and arts scene, calling him a "passionate advocate".
The Singapore Business Federation said Mr Kwek played an instrumental role in its founding in 2002.
In 1998, the Singapore Federation of Chambers of Commerce and Industry (SFCCI) was asked by the Government to examine how it could restructure itself to enhance its effectiveness and better promote Singapore's national interests.
Mr Kwek, who was then president of both the SFCCI and the Singapore Chinese Chamber of Commerce and Industry, proposed that the SBF be set up.
It was not an easy task to create an apex business chamber among existing business organisations, which had strong roots, size and financial strength, said the SBF.