A few hours later, the storm entered the Gulf of Mexico and intensified rapidly into a Category 5 hurricane while crossing the Loop Current on August 28. Katrina made landfall shortly after 06:00 CST on August 29 near the mouth of the Mississippi River as an extremely large Category 3 hurricane. Category 5-level storm surges (as the storm had weakened only in the previous several hours) caused catastrophic damage along the coastlines of Louisiana, Mississippi, and Alabama.