A ransomware attack on the Seattle Public Library has brought services to a halt — knocking out the wireless network, computers for staff and patrons, and the entire online catalog.

The incident began on Saturday, the organization said in a statement on Monday afternoon. The library has 27 different branches serving nearly 800,000 residents.

The library had been planning to take systems offline over the Memorial Day weekend to conduct maintenance on a server but discovered the ransomware attack early that morning. 

While it investigates the incident, it has taken all systems down and has contacted law enforcement. There is no estimated time of recovery. 

Libraries will still be open and will lend books and CDs manually. 

Seattle Public Library joins several city and county library systems around the world as targets of ransomware gangs — which use the demand for e-books and critical services as a wedge to make organizations pay. 

Last fall, ransomware gangs destroyed the systems of The British Library — one of the world’s largest and the national library of the United Kingdom. The Toronto Public Library spent months recovering from a ransomware attack last fall that they called a “crime scene.”

The attacks on libraries across the globe have even prompted U.S. officials to propose the creation of a program in November specifically designed to collect data about cybersecurity measures and advanced firewall services that would best help libraries defend themselves from hackers.