The Netherlands has been hit by its largest telecommunications outage in years, with the 112 emergency number knocked out across the country.
The disruption, which lasted four hours, originated from national carrier KPN, and affected other providers linked to its network.
KPN said the cause was still unclear but it did not appear to be a hack.
"We have no reason to think it was (a hack) and we monitor our systems 24/7," a company spokeswoman told Reuters.
Landlines and mobile phones linked to the KPN network were also affected, but it was the failure of the national emergency line that was most worrying. Emergency services responded by putting out alternative contact information on social media.
Speaking to public broadcaster NPO, KPN board director Joost Farwerck said the network had been backed up to prevent any malfunction, but the backups had not worked.
KPN has been told to explain to Justice and Security Minister Ferdinand Grapperhuis on Tuesday what went wrong. It has also emerged that the company's chief executive, Maximo Ibarra, is to step down, although KPN has stressed it has nothing to do with the outage.
How bad was the outage?
During the disruption, additional police were sent on to streets around the country.
Authorities also advised people to go directly to hospitals or to police or fire stations for any emergencies.
Firefighters also announced they were going out into key areas, with one fire brigade appearing at a key harbour in a Rotterdam suburb in case people needed help.
It took more than an hour for authorities to find an alternative emergency number, and even then the NL-Alert service designed to get in touch with people via their mobile phones during an emergency had problems.
The popular Telegraaf newspaper revealed that the justice and security ministry had used NL-Alert to send out the paper's WhatsApp tips-line as an alternative to 112 by mistake.
An alert was later sent out with the correct number, images of which have been posted by social media users.
Ik ben het spoor al volkomen bijster; je zal maar laaggeletterd zijn... pic.twitter.com/0v4BXp9yXv— Femke van Hemert (@FemkevanH) June 24, 2019
Mr Grapperhaus told De Telegraaf that the ministry was investigating how the wrong number was given out.
"Was it an office prank or was there really no plan?" Dutch Green politician Kathalijne Buitenweg tweeted.
What has reaction been?
Political reaction to the failure of the 112 emergency number has been one of shock.
"This just shouldn't be possible," complained centre-right MP Chris van Dam, who said it was simply incomprehensible that the 112 line was "so vulnerable".
Commentators pointed out that national security co-ordinator NCTV had warned only this month that "dependence on digitised processes and systems has become so big" that it could disrupt society and it called for "fallback options and analogue alternatives".
Many others were bemused by the failure. One social media user noted drily that politicians had been trying for years to get more police on the streets, and KPN had managed to do it in a couple of minutes.
KPN is not the only telecoms provider to suffer network problems recently. Earlier this month, Vodafone experienced a "disruption" to its mobile and fixed-line broadband services, affecting subscribers in the UK and several other countries.