Hurricane Katrina stormed on to the U.S. Gulf Coast, Monday, August 29, as a dangerous Category Four hurricane. Watch this animation to see how one of the worst storms to make U.S. landfall formed. Look below the video player for links to the news stories and photo gallery.

NASA's Tropical Rainfall Measuring Mission (TRMM) satellite captured a 3-D look inside Hurricane Katrina on the evening of August 28, 2005.

This unique look at Katrina shows the structure of rainfall inside the storm. Red represents precipitation of 2 or more inches (5 or more centimeters) per hour. Yellow represents 1 inch (2.5 centimeters) per hour. Green is a half inch (1.25 centimeter) per hour. Blue is a quarter inch (70 millimeters) per hour.