Train services broke down for the first time this year yesterday evening, affecting a four-station stretch on the North-South Line - from the station in Kranji to the one in Admiralty.
The disruption, which lasted for over an hour, was due to a traction power fault, according to transport operator SMRT.
It put out a tweet at 5.47pm informing commuters that service had been disrupted.
In response to queries from The Sunday Times, SMRT said: "Service resumed at 6.54pm. The cause is still being investigated."
It did not respond to queries on how many commuters were affected.
Train service in both directions between Kranji and Admiralty were disrupted, and SMRT had to activate free bus bridging services to move commuters between Kranji and Sembawang stations.
In addition, one train travelling in the direction of Marina South was stuck between Kranji and Marsiling stations.
Commuters were forced to get off the train and walk towards Marsiling Station. Undergraduate Vanessa Chia was one of them.
She told The Sunday Times that her train had stopped for about 20 minutes, with the air-conditioning failing during that time.
"It was a really hot day and I could hear kids crying," said Miss Chia, 20.
She added that the train was "only about a 20-second ride to Marsiling" but the distance took about 15 minutes on foot.
"A few of the passengers were quite old; it was quite painful walking on the stones for them," she said.
She added that she also saw an SMRT staff member giving an elderly man a piggyback ride.
She said that some commuters were quite agitated and were shouting.
But Miss Chia took the incident in her stride.
She snapped selfies and took videos to send to her friends.
"At first I was a little scared, but then I began to see it as an adventure. I thought it was a once-in-a-lifetime experience," she said.
"But it was lucky the weather was good and this was a weekend."
Other commuters who were affected by the breakdown took to social media to vent their frustrations.
In a Facebook post, SMRT apologised for the inconvenience, and said it had made available customised information sheets at Woodlands, Marsiling and Kranji stations "to advise commuters on alternative transport options from these MRT stations".
It added that additional staff were deployed to assist commuters and control the crowd.
The last rail incident happened onWednesday, when service on the Downtown Line was delayed because of a train fault.
It was announced last month that the Land Transport Authority would set up an expert audit panel to examine the reliability of the rail system.