The National Weather Service says last week's tornado that tore through parts of southeast Missouri and southern Illinois was an EF-4 - with top winds of 180 miles an hour - and was a half a mile wide.
The twister killed one person near Perryville, Missouri, who was thrown from his car along Interstate 55. It destroyed dozens of homes and damaged many more.
Meanwhile another tornado, which was a part of the same storm system, was rated at EF-3 with top winds of 152 miles an hour and stretching from White County, Illinois into Posey County, Indiana.
That tornado killed a man in Crossville who took shelter in an outbuilding during the storm.
At least two smaller tornadoes were also reported in the system that raked across the region Tuesday night into Wednesday. The Weather Service says one skipped along a path from just south of Carterville to just north of Marion in Williamson County, while another damaged mostly trees just southwest of Carbondale.