North South MRT line

The first section of the north south line opened on 7 November 1987 between Toa Payoh and Yio Chu Kang. Afterwards, the section to Outram Park (now on the East West MRT line) opened. Following that, the rest of the line opened stage by stage.

The Woodlands Extension was planned to close the gap between Yishun and Choa Chu Kang. It consists of 6 stations, and opened on 10 February 1996.

A 1-kilometre extension of the line to Marina South Pier MRT Station was opened in 2014.

• 7 November 1987: Yio Chu Kang – Toa Payoh
• 12 December 1987: Toa Payoh – Raffles Place
• 20 December 1988: Yio Chu Kang – Yishun
• 4 November 1989: Raffles Place – Marina Bay
• 10 March 1990: Jurong East – Choa Chu Kang
• 10 February 1996: Yishun – Choa Chu Kang
• 23 November 2014: Marina Bay – Marina South Pier
• 2 November 2019: Canberra

On 7 October, services on the line was stopped between Ang Mo Kio and Marina South Pier around 6pm, after the tunnels between Bishan and Braddell flooded following heavy rain, and a fire was seen near Raffles Place. Services between Newton and Marina South Pier was resumed at around 9.30pm but the section between Newton and Ang Mo Kio remained closed overnight. It opened at 2pm the following day after staff and the SCDF worked overnight to clear the water from the tunnel. SMRT reported that a faulty water pump was the cause of the flooding. This was the worst train incident in SMRT's history.