COORDINATORs are coordination managers for fielded first responders. Each first response team is paired with a COORDINATOR coordination manager which is running on a mobile computing device. COORDINATORs provide decision support to first response teams by reasoning about who should be doing what, when, with what resource, in support of which other team, and so forth. COORDINATORs respond to the dynamics of the environment by (re)coordinating to determine the right course of action for the current circumstances. COORDINATORs have been implemented using wireless PDAs and proprietary first responder location tracking technologies. This paper describes COORDINATORs, the motivation for them, the underlying agent architecture, implementation issues, and first response exercises.