California city declares emergency after cyberattack

Suisun City in Northern California has declared a state of emergency after malicious software compromised municipal computer systems, disrupting 911 routing, police and fire dispatch and several government services. Emergency calls continued to be answered after dispatch operations were shifted to Solano County.

The cyberattack struck at about 5.45 am on Friday, August 7, forcing officials to shut down the city’s entire information technology network. The shutdown was intended to contain the intrusion and preserve digital evidence as federal investigators began examining how the systems were breached.

The Suisun City Council approved the emergency declaration during a special meeting at 11 am on Saturday, August 8. The measure, authorised under California Government Code provisions, gives the municipality greater flexibility to obtain emergency assistance and recover costs arising from the incident.

Critical public safety operations were among the systems affected. The intrusion interfered with 911 routing, police and fire dispatch software, records and other municipal functions. City officials stressed, however, that emergency response itself had not stopped. Police and firefighters continued responding to calls while Suisun City dispatchers handled emergency communications through the Solano County dispatch centre.

City Hall remained closed to the public on Monday as the disruption entered another working day. Planning, building, housing, water, finance, human resources, public works and the city manager’s office were among departments unable to provide normal in-person services. Online municipal services and some internal operations also remained unavailable. The police department lobby continued offering limited services.

Officials have not disclosed the precise malware involved, whether information was stolen, who carried out the attack or whether a ransom demand was made. There was also no firm timetable for restoring the affected systems. Each function is being examined before it can safely be returned to the network, raising the possibility that full recovery could take considerably longer than the initial containment effort.

The FBI, Department of Homeland Security and California Governor’s Office of Emergency Services are assisting Suisun City with the investigation and restoration work. Private cybersecurity specialists have also been brought into the response as authorities examine the compromised network and determine the scale of the breach.

Suisun City, in Solano County about 55 miles north-east of San Francisco, has roughly 30,000 residents. Officials have said there is no imminent danger to the public despite the disruption. Residents could continue requesting emergency police and fire assistance, though routine municipal functions such as permit processing and water-bill transactions were affected.

The attack adds Suisun City to a growing list of municipalities dealing with disruptive cyber incidents. Smaller local governments are attractive targets because they operate networks containing financial information, employee records, permitting systems and public-safety applications while often having fewer cybersecurity resources than large government agencies or major companies.

Another Bay Area municipality, Foster City, declared an emergency in March after a ransomware attack disrupted government systems and temporarily affected police and emergency communications. Much of its network was taken offline while cybersecurity specialists investigated suspicious activity. Oakland suffered a major ransomware attack in 2023 that disrupted municipal operations and led to the exposure of sensitive information belonging to city employees.

The Suisun City incident is particularly significant because of its impact on systems connected with emergency communications. A successful intrusion does not need to disable emergency responders themselves to create serious operational risks. Loss of dispatch software, digital records or communications infrastructure can force agencies onto backup procedures and increase dependence on neighbouring jurisdictions.

Suisun City’s ability to reroute calls through Solano County demonstrated the importance of maintaining alternative communications arrangements during an information technology failure. Officials said its systems were also configured to shut down automatically after detecting an intruder, helping isolate the compromised network rather than allowing malicious software to continue spreading.

Investigators must now determine how access was gained, what systems were reached and whether information was copied before the network was isolated. Those findings will influence how quickly municipal computers can be restored and whether residents or city employees need to take additional protective measures.