Hurricane Hilda was an intense tropical cyclone that ravaged areas of the United States Gulf Coast, particularly Louisiana. In addition to its damage inland, the hurricane greatly disrupted offshore oil production, and at its time was the costliest tropical cyclone for Louisiana's offshore oil production. Due in part to flights made by the National Hurricane Research Laboratory, Hilda became one of the most well-documented storms meteorologically in the Atlantic. Lasting for seven days as a tropical cyclone, Hilda caused US$126 million in damage and 38 deaths. It was the tenth named storm, sixth hurricane, and the fourth major hurricane of the 1964 Atlantic hurricane season.