Hurricane Carla tornado outbreak

Hurricane Carla triggered a destructive and deadly outbreak of 21 tornadoes in Alabama, Louisiana, Texas, Arkansas, and Michigan that occurred from September 10–13, 1961. A total of 11 tornadoes touched down in Louisiana, and eight more in Texas. The strongest tornado of the outbreak was a 1 mi long, 100 yd wide F4 tornado that moved across Galveston Island in the early morning hours of Tuesday, September 12, 1961, killing eight people. This was the first of only two known violent tornadoes ever spawned by a hurricane with the other one happening during Hurricane Hilda in 1964. By the time it was over, the outbreak had killed 14 people, injured 337 others, and caused over $3.461 million in damage.

Meteorological synopsis
As Hurricane Carla moved northwestward over the Gulf of Mexico on September 10, its outer rainbands began to spread over the Gulf Coast. Favorable shear profiles led to scattered tornadoes touching down across the region, including an F3 tornado that caused numerous casualties in Kaplan, Louisiana. More tornadoes touched down the next day as the system made landfall in Port O'Connor, Texas at peak intensity with 145 mph winds and a pressure of 931 mbar. September 12 was the worst day of the outbreak with six significant (F2+) tornadoes touching down, including a violent F4 tornado in Galveston, Texas and an intense F3 tornado in Jonesboro, Louisiana, causing widespread destruction and 250 casualties. By September 13, a weaker Tropical Storm Carla was accelerating northward into Canada. Some scattered tornado activity occurred on this day before the outbreak came to an end.