Every state has adopted some form of a government immunity statute that generally provides that, except in limited types of cases, city governments can not be sued. In those limited cases where the government has "waived immunity" (meaning allowed itself to be sued), the statutes typically specify strict notice and procedural requirements.
Suing a City Government
Find a good attorney reference who can answer your questions and help provide you forms to use in your lawsuit. If you don't have a family member or friend who is an attorney, think about hiring an attorney on a "limited representation" or "unbundled" fee arrangement to save costs.
Locate and read your state's government immunity statute. You need to determine whether government immunity has been waived for the type of case you want to pursue.
File a notice of claim with the city you want to sue. Most state laws require a notice of claim to be filed within one or two years of the action giving rise to the claim, so make sure you check your state's deadlines and then stay on top of your deadline.
Wait for the city to review and answer your notice of claim. Most state laws require the city to either accept or deny your claim within a certain amount of time after you file the claim, such as 60 days.
If the city denies your claim, check your state law and City Code to determine whether you must appeal to the city level before filing a lawsuit in court. Some states require one more appeal at the city level, but most states allow you to file a lawsuit immediately after your claim is denied.
If the city denies your claim, you can then file a lawsuit in a court of general jurisdiction in the county where the city is located.