IT and phone systems are back online after a critical incident caused an outage for Royal Sussex County and Princess Royal hospitals in Sussex, UK.

The hospitals began experiencing problems on January 14 after what the chief medical officer at the University Hospitals Sussex NHS Foundation Trust, Professor Katie Urch, described as a "very dramatic" incident.

– Sussex Partnership NHS Foundation Trust

The issues were caused by a power outage in an IT room housed at the Princess Royal Hospital, which temporarily shut down all IT systems at both sites.

Ambulances were forced to divert to other hospitals, and the general public was warned not to attend A&E unless it was a "lifesaving" emergency.

The outage commenced at 6pm GMT, and by 11:30pm "progress" had been made in restoring the IT services. Some issues remained ongoing, however, and it wasn't until 9am January 15 that the trust was no longer in a "critical incident."

The 9am update said: "Our Emergency Departments are receiving patients as normal, but please be aware that all teams are under additional pressure after the disruption over the weekend – if your health problem is not an emergency, or life-threatening, please visit or call 111 for help or advice.

“Once again, we would like to say thank you to everyone who has responded so brilliantly – our colleagues in IT and Facilities and Estates, our clinical teams, the South East Coast Ambulance Service, and other NHS trusts and partners.”

According to a BBC report, Author and veteran foreign correspondent Malcolm Brabant was at the Royal Sussex visiting a relative when the system crashed.

Brabant told the BBC: "Aeroplanes have backup systems to make sure they don't fall out of the sky. Why, when you have a massive new hospital that costs £500m ($631.7m), do you not have a backup system? Lives could be put at risk by this. It smacks of really bad planning and incompetence."

Nottingham University Hospital experienced a similar outage in October 2023. Last year also saw IT outages impacting hospitals in New Zealand and Western Australia, and the Veterans Affairs Medical Center in Kansas City suffered a four-hour IT outage after a cat jumped on a keyboard, deleting a server cluster.

In 2022, London-based Guy's and St Thomas' NHS Foundation Trust suffered a significant outage during a summer heatwave leaving doctors unable to access patient medical records, and ultimately costing the NHS around £1.4m ($1.7m).