Sentosa's monorail service was hit by a track switch fault on Tuesday night, disrupting service until yesterday morning.
In response to queries from The Straits Times, the Sentosa Development Corporation (SDC) said the fault had prevented trains from entering the VivoCity station.
The Sentosa Express monorail service runs from 7am to midnight daily. Service was affected for about five operational hours, from 9.40pm on Tuesday evening to 9.40am yesterday morning.
An SDC spokesman said: "Guest experience is of utmost importance to us, and we apologise for any inconvenience the temporary service disruption may have caused.
"We are working closely with our contractors, engineers and partners to enhance preventive measures and conduct a review of this incident to ensure that Sentosa's transportation network runs smoothly."
Sentosa announced the disruption in a post on its Facebook page at about 10.50pm on Tuesday.
The SDC spokesman told ST that free shuttle buses were immediately activated to ferry guests between Beach Station on Sentosa and HarbourFront Bus Interchange.
Visitors to Sentosa were also able to use existing options such as buses and the cable car service to get to and around the island during the disruption.
The Sentosa Express runs between four stations, spanning VivoCity, Resorts World Sentosa and the island's major beaches.
In December 2014, a technical fault caused a monorail train on the line to stall, leaving 61 passengers stranded in the train for over an hour before they were evacuated.