Usually, the authorities in American cities introduce an emergency mode only because of natural disasters.
The authorities of New Orleans have introduced an emergency regime due to a cyberattack on the system of urban websites. The mayor of New Orleans Latoya Cantrell wrote about this on his page on Twitter.
According to her, many city services servers were disconnected due to a ransomware virus attack. To solve the problem, experts from the FBI, the Secret Service, and the National Guard were involved.
As a rule, the authorities of American cities introduce emergency mode only because of natural disasters. This allows them to rely on federal resources.