In general, in $k$-covered wireless sensor networks (WSNs), whenever an event occurs, $M\;\left(\geq k \right)$ sensor nodes, lying in the communication range (CR) of each other, have data packets to send in the same cycle. In the existing cross-layer contention-based synchronous MAC protocols, very few nodes can forward their data packet in the same cycle when $M$ nodes, with data packets to send, lie in the CR of one another. This results in a drastic increase in the end-to-end transmission delay (E2ETD) with increasing $M$. In this article, we propose a low delay, cross-layer contention-based synchronous MAC (LDCMAC) protocol for event driven WSNs. LDMAC increases the number of nodes that can forward their data packet in the same cycle when $M$ nodes, with data packet to send, lie in the CR of one another. We evaluate LDCMAC through NS-2.35 simulations and compare its performance with the CL-MAC protocol. Results suggest that LDCMAC significantly outperforms CL-MAC in terms of E2ETD and packet delivery ratio (PDR).