The National Weather Service says the April 11 tornado that traveled northeast through Mississippi's Kemper and Noxubee counties and into Alabama's Pickens County had a 68 mile-track.
The Weather Service's Jackson, Miss., office says peak storm winds were 145 mph.
The twister killed Carlos Madrigal, of Blue Mountain, Miss., at Contract Fabricators Inc. north of DeKalb. The NWS summary also says it injured nine people.
The maximum width of the path was three-quarters of a mile.
The team that examined the path said that besides the destruction at Contract Fabricators, the worst damage included a destroyed home west of DeKalb, areas around Shuqualak where buildings were damaged and high-tension electrical lines were bent, and a radio tower near Prairie Point that crumpled to the ground. Thousands of trees were snapped or uprooted.