Smart grids are critical cyber-physical infrastructures in the world now. Since these infrastructures are prone to large scale outages due to disasters or faults, a resilient and survivable communication architecture is desired. In this work, we propose a resilient and survivable hierarchical communication architecture for the smart grid that mirrors the hierarchy of the existing power grid. Post-disaster resilience in grid communication is achieved through the grid flattening process. This process involves smart-meters and other disaster surviving elements of higher system levels of the grid forming a wireless mesh network. The flattened network of grid elements with one-hop communication links help in reliable and timely relaying of grid's health information to working regions of the grid. This allows for swift action by control engineers of the utility provider and emergency services with real-time data. We propose analytical models to study the performance of the flattened architecture as a function of outage area, smart-meter density and smart-meter's neighborhood size. The results from the analytical model will be compared with simulation results from OPNET.