In this paper, we propose the coordinated robust routing (CRR) scheme to address the fault tolerance requirements in the layered wireless sensor networks. In the proposed scheme, the robust routing trees are constructed coordinately from the most outward layer all the way to the sink node. The coordination is achieved by selecting two dedicated cluster heads for every two clusters in one layer. The problem of selecting dual cluster heads is formulated as a transportation problem, which can be solved using network flow algorithms. By having two cluster heads for every cluster pair, the CRR scheme helps to achieve fault tolerance and energy efficiency with low degree of network redundancy as well as low inter-packet delay. The performance of the CRR scheme in terms of delay, energy consumption, and network lifetime has been confirmed through simulations and compared with the single cluster head scheme. Keyword: Wireless sensor networks, fault tolerance, energy efficiency, cluster, r...