In in-network data aggregation in Wireless Sensor Networks (WSN), selection of communication paths and aggregation points are critical network requirements. They enable efficient use of network resources in constrained environments. Base Station (BS) driven routing protocols are prime enablers to implement such network requirements. In Base Station (BS) driven routing protocols the BS proactively finds a path to communicate with each node in the network. However, if a node in the network fails or goes to sleep; the communication path between the BS and some nodes in the network is disabled and these nodes are disconnected from the BS. In this paper, an algorithm to reestablish a communication path between these disconnected nodes and the BS, is proposed. The reestablishment of paths add fault-tolerance; and facilitate retention of connectivity of the nodes in the network to enable communication with the BS. The results demonstrate the merit of the proposed algorithm.