After running for 4 months, the train line broke down yesterday morning.
Train operator SBS Transit cannot explain why the emergency brakes on a train were applied for no apparent reason, and why the brakes could not be disengaged.
The fault took place at 11am and took about 30 minutes to resolve.
The affected train held up services between Bukit Panjang and Sixth Avenue stations.
As a result, SBS Transit had to deploy buses to ferry affected commuters.
SBS Transit is investigating the incident.
Meanwhile, Singapore’s other train operator, SMRT, was also hit by service distruptions.
A train fault at Toa Payoh station along the North-South Line at about 5.45pm delayed northbound service towards Jurong East.