Sutter Health’s information and communications network is back up and running after the California hospital giant experienced a systemwide failure late Monday that crippled its electronic health records.

The network went back online at 2 a.m. Wednesday, more than 27 hours after the initial outage, Sutter Health officials and staff said. It began around 10:30 p.m. Monday and affected all 24 hospitals in the Sutter system.

Nancy Turner, a Sutter Health spokeswoman, said the outage was caused by the activation of the fire suppression system in one of Sutter’s data centers.

“Our technical teams worked around the clock to resolve this issue and fully restore system access,” she said in a statement Wednesday. “All Sutter Health data remains secure.”

Throughout the day Tuesday, Sutter staff said they couldn’t access patient history information or the health system’s policies and procedures, which are kept online.

One nurse at Sutter Santa Rosa Regional Hospital said the network failure caused hospital staff to completely revert to paper medical charts and forms. Night shift nursing staff “had to do a ton of data entry,” she said.

She said management staff now is tasked with inputting into the computer systems the patient information recorded on paper throughout Tuesday. Sutter officials said patient safety was of primary concern during the network outage. No surgeries at Sutter Santa Rosa Regional Hospital were canceled or delayed and patients were being seen, but several Sutter facilities in Northern California had to cancel some surgeries.

“We apologize for any challenges this situation may have caused, and we appreciate the dedicated work of our caregivers and staff in following downtime processes,” Turner said.

You can reach Staff Writer Martin Espinoza at 707-521-5213 or martin.espinoza@pressdemocrat.com. On Twitter @renofish.