(CNN) -- Lee Kuan Yew, who is widely credited with molding Singapore into one of the world's most prosperous countries, has been admitted to the hospital, officials said.
Lee, 87, was the founding father of the island nation. His son, Lee Hsien Loong, is now Singapore's prime minister -- the country's third since it gained independence from Malaysia in 1965.
The elder Lee was admitted to the Singapore General Hospital on Wednesday evening for a chest infection, a spokeswoman said Thursday. She did not offer further details on his hospitalization.
Lee took a spill on Monday and had gone to the hospital on Tuesday for physical therapy but was able to speak at a business forum on Tuesday night.
Then-businessman Lee took over the helm of the swampy seaport of Singapore in 1959 and governed through the race riots of the 1960s.
He also molded Singapore into a major transport and financial services hub, with its port becoming one of the busiest around the globe.
But he also created a Singapore bound by stringent laws and regulations that dictated most, if not all, aspects of society -- including media and political freedoms, censorship and even the selling of chewing gum.
The elder Lee voluntarily stepped down in 1990 -- the first Southeast Asian strongman to do so -- and turned power over to Goh Chok Tong.
Goh ran a "kinder, gentler Singapore" and helped dilute the perceptions of a Lee family dynasty.
After 14 years in power -- steering Singapore through the 1997 financial crisis and the SARS outbreak, and reaching out to his neighbors and to the West -- 63-year-old Goh turned the office over to Lee's son in 2004.