Google posted before-and-after images of the devastation left behind by the tornadoes that hit the South and parts of the East Coast of the United States earlier last week, with close-up views particularly of Tuscaloosa, Alabama.
When you search for some areas impacted by tornadoes in Google Maps, the search company also triggers a special alert that leads to maps of where tornadoes touched down and Red Cross shelters. Here you can see it happening for a search on Concord, Alabama:
Below is a montage photo of before and after for both Tuscaloosa, Alabama and Jefferson County, Alabama:
Here's the Picasa Web Alubums slide show of the tornadoes images:
The National Oceanic & Atmospheric Administration also has a useful site about the April 2011 tornadoes in general. Along with many facts, the site also contains an image showing tornado tracks color-coded to show where the strongest ones were. Yellow is strong; orange stronger and red shows the most severe:
More Info: NOAA site