More than 300 people were killed by more than 180 tornadoes in late April, 2011. This historic outbreak, like many that came before it, now ranks as the most thoroughly-documented tornado outbreak in United States history. With ever-advancing technology including GPS, high-resolution satellite imagery, and instant communication, such documentation of the outbreak spans far beyond the limits of just one newspaper column or one television account.
The National Oceanic & Atmospheric Administration is preparing comprehensive archive of the April 2011 tornado outbreak. You’ll find the NOAA site here. 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:

Other imagery has been taken from space to track the impact of the tornado outbreak on the Southeast United States. Visible imagery — essentially, high-resolution color photographs — taken from space show the scars left across the ground by the devastating storms. Click the image for a larger view:

Additionally, infrared satellite imagery–imagery that detects the temperature of the ground and clouds–also displays the scouring of the ground by the storms:

After recent disasters such as the 2004 Indonesian tsunami, Hurricane Katrina in 2005, and now the 2011 tornado outbreak, Google has created a library of riveting paired photographs that display areas both before and after the storm. Here’s a sample:
