Football fans all over Sweden settling down to watch the semi final of the European Champions League were among the first to notice the downtime as they came face to face with a blank screen as kick-off loomed.
PTS said it would begin its investigation on Wednesday by requesting information from Com Hem as to what had caused the outage.
“This was an outage that affected 800,000 subscribers in all, so we view it as a serious incident that we need to investigate,” said Christoffer Karsberg, head of the agency’s network security department, to news agency TT.
The most serious aspect concerned the IP telephony outage and a lack of access to the emergency services number, 112.
“We’re now beginning our inspection and will find out what happened: how Com Hem resolved the incident, how the 112 service was affected and, above all, how they can ensure that there won’t be any similar incidents in the future,” said Karsberg.
The Swedish Civil Contingencies Agency (Myndigheten för samhällsskydd och beredskap – MBS) also viewed Tuesday evening’s developments with a degree of concern.
“It’s worrying that more and more services are tied to a single cable as it makes us more vulnerable, and we have probably only seen the beginning of this development,” said security analyst Svante Nygren.
Recent developments have meant that telecom outages are now a security issue affecting society as a whole, he added.
“A telecom outage today is not the same as telecom outage 10 or 20 years ago, as now internet and media distribution are also affected, as are the possibilities of contacting the police, rescue services and ambulances,” said Nygren.
Com Hem said the central facility used to distribute the company’s services was hit by a blackout at 8pm.
By 10pm, Manchester United and Arsenal’s players had finally returned to all the living rooms of Sweden.
“Our broadband and IP telephony services have been working since 11pm,” said Com Hem spokeswoman Maria Stråhle.
Com Hem CEO Tomas Franzén admitted it was unacceptable that a single power cut could wipe out the company’s nationwide services, adding that the company would now take time to review its security provisions.
“We need a chance to investigate the situation. We have put all our energies so far into getting the services back up and running, that has been our top priority,” he told Sveriges Television.