Failure of landline and internet networks

A "massive outage" left parts of Denmark without phone service or an emergency call system.
Thousands of people across the country reported being unable to make calls earlier today, including to 112, the emergency number.
Police in Funen, the country's third-largest island, set up patrols in the streets to help residents.
According to the Copenhagen Post, this was due to service issues with telecommunications company TDC which is currently investigating.
At the same time, significant disruption to train services were reported in parts of Denmark.
X user Jürgen Nauditt reported: "Chaos in Denmark - no mobile phone service, trains at a standstill. According to media reports, there has been a widespread failure of the mobile phone network in Denmark. The emergency call system is also said to have failed. The Danish railway is also out of service, trains have stopped on the open track."
Another X user, @imurpartha, wrote: "ALERT: Denmark's Communication crisis! Mobile phones down, trains halted. Emergency services are in the dark."
The Copenhagen Post reports that "trains in large parts of Jutland have been suspended following issues with Banedanmark’s digital signaling system.
"The affected lines include Esbjerg-Holstebro, Vejle-Struer, and Aarhus-Aalborg, among others."
Banedarnmark is a governmental body which is responsible with the maintenance of the state-owned Danish railway network.
The disruption lasted for several hours, but it is understood that services have now resumed. Cancellations and delays are still to be expected this evening.
It is not known what caused the issue at this stage.