HATTIESBURG, Miss.--The tornado that hit Hattiesburg Sunday was upgraded to an EF4 Monday, one of the stringest categories. The highest level is an EF5. The twister that hit Hattiesburg and the University of Southern Mississippi had winds of 170 mph when it hit the Oak Grove community in Lamar County, according to survey teams from the National Weather Service.
The tornado was on the ground for 20 miles. There were 83 injuries with the tornado. Nineteen of those were in Lamar County.
It was a seperate tornado that struck a mobile home park in Lamar County, totally destroying at least three of the trailers and causing two critical injuries. That tornado was rated an EF2, which is still a strong tornado. Winds were estimated at 115 mph. It was on the ground for over 13 miles.
The Hattiesburg twister was given an EF4 rating when it was discovered that a well-built brick home was leveled, consistent with very high winds.
Tornadoes are rated on a scale that estimates wind speed from the damage that occurred. The scale was developed in the 1960s and 70s.