Government agencies have many important responsibilities to protect the safety of citizens. The government is responsible for designing and maintaining roads, for maintaining public parks and sidewalks, and for operating public transportation and local school buses. These are just a few of the tasks local and municipal governments are entrusted with performing. Whenever a government agency is given a job to do for the public, it is expected to do it competently.
If someone gets hurt because the agency does not do its job, this can sometimes give rise to legal liability. However, unlike suing a private citizen or suing a private corporation, government entities get some special protections under the law. The protections afforded government workers and agencies are referred to as sovereign immunity.