As it moved slowly across the Gulf of Mexico, Carla got stronger to its peak of 175 mph (280 km/h) winds (Category 5 intensity) on September 11. Just before landfall, it weakened, but Carla was still a very strong and unusually large Category 4 hurricane when it touched the shore between Port O'Connor and Port Lavaca, Texas, on the 11th. At the time, Carla became the largest hurricane on record in the Atlantic basin. Along the whole Texas shore, hurricane warnings were given, and people were moved out of their homes in low-lying areas.