This Technical Bulletin was prepared by the Tennessee Municipal League (TML) Risk Management Pool loss control staff, and it discusses the importance of mutual aid agreements. With these pacts, cities and various other governments (other cities, counties, etc.) agree beforehand about helping each other when aid is needed. Most importantly, these agreements authorize such aid and thus protect the entities from unlimited liability.
Tennessee Municipal League Risk Management Pool, "Mutual Aid and Emergency Assistance: An Update" (1992). MTAS Publications: Technical Bulletins.