This paper addresses the sensor network scenario where several nodes sense a common information source S. When such sensors forward their correlated observations to a common shared receiver, it is necessary to combine the received information in order to obtain an estimation of S with high reliability. In this manuscript we propose the use of low-complexity concatenated Zigzag codes for the transmission of correlated sensors through orthogonal AWGN channels. In reception, a novel albeit simple correlation estimation procedure is integrated into the iterative decoding and data fusion algorithm, which is based on the Sum-Product Algorithm applied over the factor graph describing the system. Fundamental limits are also derived for the end-to-end probability of error. Simulation results verify that the Bit Error Rate (BER) performance of the proposed receiver is very close to the aforementioned fundamental limits, while requiring less decoding complexity than other capacity-approaching codes.