Original: The next day, the tropical depression strengthened to a tropical storm, and was named Katrina; it proceeded to make landfall on the southern tip of the U.S. state of Florida as a minimal hurricane.
Simplified: The next day, the tropical depression strengthened to a tropical storm, and was named Katrina. Katrina continued on to make landfall on the southern part of the U.S. state of Florida as a Category 1 hurricane.