  Recent advances in wireless sensor networks (WSNs) have led to many new
promissing applications. However data communication between nodes consumes a
large portion of the total energy of WSNs. Consequently efficient data
aggregation technique can help greatly to reduce power consumption. Data
aggregation has emerged as a basic approach in WSNs in order to reduce the
number of transmissions of sensor nodes over {\it aggregation tree} and hence
minimizing the overall power consumption in the network. If a sensor node fails
during data aggregation then the aggregation tree is disconnected. Hence the
WSNs rely on in-network aggregation for efficiency but a single faulty node can
severely influence the outcome by contributing an arbitrary partial aggregate
value.
  In this paper we have presented a distributed algorithm that reconstruct the
aggregation tree from the initial aggregation tree excluding the faulty sensor
node. This is a synchronous model that is completed in several rounds. Our
proposed scheme can handle multiple number of faulty nodes as well.
