Fact: No. Cities are not required to maintain a certain level of public safety staffing. They are required to hire, train, equip and respond to incidents within regulatory and professional standards. Put another way, first responders are not obligated to provide services to an individual citizen (or neighborhood) but are only obligated to provide services to the public at large. As an example, the Fountain Valley Municipal Code authorizes the police chief to set staffing levels at whatever level the chief feels appropriate. Courts have recognized this discretion rests solely with policy makers such as a police or fire chief or an elected City Council.
Don’t police officers or firefighters have any duty or responsibility? Of course they do; it’s called a “public duty doctrine”. This legal duty does not involve setting staffing at a particular level. A police officer’s duty to act affirmatively to, for example, perform CPR or make an arrest- is only mandated if a “special relationship” exists, which is a high standard to meet.
In summary, cities are not required to set staffing at given levels, even for first responders, and are under no threat of liability in this scenario.