When line workers restore power, they give priority to the lines that will get the most people back in service as quickly as possible. Ever wonder how they do it? Take a look!
good question for the relative low voltage distribution networks in towns and cities, but once you get into super-high voltages necessary for "power grid" national transmission it can't be underground because the transmission power losses through the ground would be prohibitive using our current technologies. Maybe sometime in the distant future if they perfect superconductor wiring that can be produced and buried at a cost effective price it might be doable, but at the present it's not possible.