In 1990, Goh Chok Tong replaced Lee Kuan Yew as prime minister, while Lee Kuan Yew became Senior Minister. When Goh Chok Tong was Prime Minister, Singapore went through the 1997 Asian financial crisis, the 2003 SARS outbreak and terrorist threats by Jemaah Islamiyah. In 2004, Lee Hsien Loong, the son of Lee Kuan Yew, took over as Prime Minister. Goh Chok Tong became the Senior Minister, and Lee Kuan Yew became the Minister Mentor of Singapore. Lee Kuan Yew died in 2015.