We study the supervisory control of timed discrete event systems (TDESs) communicating via unbounded FIFO channels. We model a local TDES by a finite-state automaton with a special event of the global clock. A local supervisor observes the events generated by the corresponding local TDES, and estimates the current state of the other local TDESs based on the synchronized global clock and the received events. We study the state avoidance problem, and propose a distributed control algorithm for the local supervisors to collectively control the global system not to reach a given set of undesirable states.