Additionally, it would be unfeasible to change the position of the station, because moving it south would render it too close to Toa Payoh MRT station, while moving it north would be impossible because of surrounding HDB blocks and JTC Flatted factories.

This case of water entering MRT tunnels is believed to be the first time it has affected train service along the NSL.

Separately, at about 5.55 pm, a small fire was spotted trackside in the tunnel between the Marina Bay and Raffles Place stations, but it had died down by itself.

It is not clear if it is linked to the flood, although electrical short circuits caused by water had sparked tunnel fires before.

Train services between Newton and Ang Mo Kio were fully resumed at 1.36 pm the following day after overnight efforts to clear the water in the tunnel, after nearly 21 hours of service disruption, being one of the worst disruptions in SMRT Trains Ltd's history.