Human error was behind last month's fire at a major SingTel Internet exchange which crippled essential services across Singapore, the telco said on Wednesday.
Its preliminary investigations showed that the Oct 9 fire at its Bukit Panjang facility was caused by a SingTel employee's use of an "unauthorised" blowtorch during "maintenance work" - which did not follow strict procedures.
A SingTel spokesman declined to reveal more on the blowtorch and why it was needed, pending an on-going review by the telco's committee of inquiry (COI).
The COI, comprising members of SingTel's board, is expected to recommend steps to prevent a similar incident, and will also decide on how to discipline the employee, who has been suspended, added the spokesman.
SingTel, which will be announcing its second-quarter financial results next Thursday, said it treats the incident "very seriously".
It added that it has always ensured that its contingency plans and safety measures meet global benchmarks.
Since the incident, the telco has taken several measures, including reinforcing training on safety rules and limiting any maintenance work which requires the use of high temperatures.
On Wednesday, SingTel group chief executive Chua Sock Koong also apologised to its customers, saying it recognised the importance of reliable communication services, and Singapore's status as a leading financial and business hub. "We are committed to learning from this experience and welcome recommendations from the COI and independent experts to enhance our operations."
Acknowledging SingTel's preliminary findings, an Infocomm Development Authority spokesman said it was conducting its own investigation and will make its findings known in due course.
The blaze at the facility - one of SingTel's nine major exchanges - affected services at DBS branches and ATMs, SingHealth polyclinics, Singapore Pools branches and AXS payment machines, along with 60,000 SingTel home broadband users, the bulk of whom are also mioTV users.
StarHub and M1 home fibre broadband services were alsodisrupted as they buy wholesale fibre links from national fibre broadband network builder OpenNet.
Two-thirds of the 149 fibre optic cables which were damaged in the fire belonged to OpenNet.
Some StarHub cable TV and cable broadband users were also affected by the SingTel fire, as StarHub leases SingTel fibre links for portions of its cable network.
It took more than a week to get OpenNet's services running again, although all of SingTel's corporate customers were reconnected almost two days after the fire.
Get a copy of The Straits Times or go to straitstimes.com for more stories.