The 3G network was down, with users saying they could not get mobile services in many areas, including Choa Chu Kang, Ang Mo Kio, Yio Chu Kang, Yishun and Jurong West.
Get the full story from The Straits Times.
UPDATE: M1 has issued the following statement regarding the outage
SINGAPORE - During a transmission equipment upgrade by one of our vendors at 3:00am this morning, a power incident at our network centre set off the gas suppression and water sprinkler systems, which in turn caused an outage to one of our mobile network switches. This affected the 3G network entities connected to the switch and resulted in the loss of 3G mobile services to some of our customers in the South-Western parts of Singapore, namely West Coast, Jurong and Tuas areas.
The 2G network entities are connected to another switch and as such, were not affected. In this instance, 3G phones of affected customers will automatically switch to the 2G network. The majority of 4G phones will require customers to turn off the 4G service manually on their devices, and this will prompt the terminals to fall back to the 2G network.
We have updated customers through the M1's corporate website, Facebook and hotline, and will continue to provide regular updates.
To restore services, we have connected the network entities to a working switch and are conducting final stages of testing. Actual migration of traffic from the affected switch will take place progressively.
"We sincerely apologise to our affected customers for the inconvenience caused, and thank them for their support, understanding and patience. Please be assured that our top priority is to resolve this issue as quickly as possible," said Karen Kooi, Chief Executive Officer, M1 Limited.
"Added measures will be put in place to prevent recurrence of such incidents," added Ms Kooi.