A woman takes photos of cards for former Singaporean prime minister Lee Kuan Yew, placed at a well-wishing corner at the Singapore General Hospital in Singapore on March 23, 2015. Reuters/Edgar Su

Update 6:42 p.m. EDT: U.S. President Barack Obama issued a statement after Lee's death and offered his condolences. The following was issued by the White House:

"I was deeply saddened to learn of the death of Singapore’s Minister Mentor, Lee Kuan Yew. On behalf of the American people, Michelle and I offer our deepest condolences to the Lee family and join the people of Singapore in mourning the loss of this remarkable man. A visionary who led his country from Singapore’s independence in 1965 to build one of the most prosperous countries in the world today, he was a devoted public servant and a remarkable leader. Minister Mentor Lee’s views and insights on Asian dynamics and economic management were respected by many around the world, and no small number of this and past generations of world leaders have sought his advice on governance and development. I personally appreciated his wisdom, including our discussions during my trip to Singapore in 2009, which were hugely important in helping me formulate our policy of rebalancing to the Asia Pacific. He was a true giant of history who will be remembered for generations to come as the father of modern Singapore and as one the great strategists of Asian affairs."

Original story:

Lee Kuan Yew, Singapore’s founding father and first prime minister, died early Monday, the Wall Street Journal reported. He was 91. Lee battled “severe pneumonia” since he was admitted to a hospital Feb. 5.

Lee is credited with forming the People’s Action Party in 1954. He then became prime minister of Singapore in 1959 and helped facilitate its independence from Britain in 1965.

"The prime minister is deeply grieved to announce the passing of Mr. Lee Kuan Yew, the founding prime minister of Singapore. Mr. Lee passed away peacefully at the Singapore General Hospital today at 3:18 a.m. He was 91," incumbent Prime Minister Lee Hsien Loong announced, Channel News Asia reported.

Lee served as prime minister until 1990, when he stepped down. More than a decade later, he shared his legacy in the 2011 book, “Hard Truths To Keep Singapore Going.”

"It's irrelevant to me what young Singaporeans think of me," he said. "I've lived long enough to know that you may be idealized in life and reviled after you're dead." Young or not, plenty of Singaporeans came out to place flowers outside the hospital after news of Lee’s declining health broke -- a testament to how much the political figure was beloved.

As prime minister, Lee’s main goals were to make Singapore a “clean and green” country, Reuters reported. For example, it’s illegal to chew gum there, partly keep the pavement clean. Though Singapore has a legalized sex industry, porn is illegal.

During his time in office, he focused on economic-friendly policies and social order, which ultimately attracted some of the world’s richest companies and helped transform Singapore from a developing country to one with a thriving economy.

Lee is survived by two sons and a daughter.

Follow me on Twitter @mariamzzarella