This article notes that the only working telecom infrastructure left in New Orleans after the storm was cheap wireless. And even today, WiFi is playing a big role in the city's recovery. In areas prone to flooding, WiFi has an advantage because it is usually installed on something that is above the flood levels. If you can get power to it, it works. And there are some WiFi hotspots powered by batteries and solar power, making them even more resistant to power outages.
I was on the phone today talking with some folks about the direction of infrastructure in rural communities, and the consensus was that no matter how good wireless gets (in terms of bandwidth), you will still need fiber to provide a backbone. Paradoxically, as wireless bandwidth capacity increases, you need fiber more, not less.
All that wireless bandwidth eventually has to hop back onto the wired Internet, and so you will need a fiber backbone, not something lashed together using copper T1 and DSL lines (which is common today).
Every community is different, so there is no one way to start investing in broadband infrastructure, but one rule of thumb does hold true everywhere: don't put all your eggs in one basket.