Millions of Three customers in Ireland suffered a lack of mobile text, data and voice calls on bank holiday Monday due to a datacentre failure.
Three told V3 in a statement that the problem was caused by an electrical failure that created a faltering 2G and 3G network.
"The service issue experienced by some customers yesterday has been resolved. The issue arose due to an electrical failure at one of our data centres. We would like to thank those affected for their patience and we apologise for any inconvenience caused," Three said.
"Some customers had been experiencing intermittent 2G and 3G service issues. This had occurred due to an electrical failure at one of our data centres which caused an increase in temperature in the building and then subsequently impacted some systems affecting customer service."
Three also related the incident on its Twitter page, informing users of the incident as it occurred. "Some customers may be experiencing issues with their service. We're working on getting this fixed as soon as possible. Sorry for any inconvenience caused," Three said.
The operator returned to the problem five hours later, explaining that it was still ongoing.
"We're aware that customers may be having service issues. Work to resolve this will continue tonight. We'll be back online tomorrow at 9am," Three explained.
The company confirmed a full return to service at around 6.30am on Tuesday with an update on its Twitter page.
The issue with service has now been resolved. Thanks for your patience, we apologise for any inconvenience caused.— Three Ireland Online (@ThreeCare) April 7, 2015
The Irish Independent said that the problem affected around two million of Three's six million customers and lasted for most of Easter Monday and into Tuesday.
Three recently agreement to a deal to acquire O2 in the UK for £10bn, a move that was made just a few weeks after BT agreed to buy EE for £12.5bn as the UK mobile market prepares for a major overhaul.
New regulation expected to cut greenhouse gas emissions by about 17 million metric tonnes between 2020 and 2050
Molybdenum ditelluride is a two-dimensional material that can be easily stacked into multiple layers to create a memory cell
New light-guiding nanoscale device can control and monitor a nanoparticle trapped in a laser beam with high sensitivity
Optical traps are scientific instruments in which a focused laser beam is used to exert an attractive or repulsive force on a microscopic object to hold it in place
Scientists estimate that the exoplanet has already lost up to 35 per cent of its mass over its lifetime