The damage wrought by Sunday's tornado in Vilonia, Arkansas, destroyed so many landmarks that long-time residents were left puzzled by where they were, a storm chaser said.
Greg Johnson arrived in the town near Little Rock just hours after the twister - one of 31 across the Plains and South - turned communities to matchsticks Sunday.
From his initial assessment Johnson said the damage appeared consistent with an EF4 or EF5 strength tornado, the two highest categories.
"To give you an idea of what's left of the town, when we pulled up last night we had people who had been living here for years coming up to us and asking, 'Do you know what street we are on?'" said Johnson, who has been chasing storms for a decade.
"This tornado left behind no visible landmarks in some areas and people just did not know where they were."
He added: "When you see photos of nuclear bomb explosions and the total destruction they cause, what we are seeing in areas here is certainly comparable to that. It's like it has been hit with an atomic bomb - totally flattened."
Johnson said the tornado appeared to be worse than one which hit the town three years ago to the week, on April 24, 2011, and killed four people. That twister was an EF2.
Two factors that made the damage in Vilonia particularly bad this time, he said, were that the twister struck the town after dark, and the town's shape.
"While tornadoes do cause damage along a path, this town is a long, thin type of town built mainly along one road. This appears to be the rough path along which the tornado traveled."
Based in Regina, Saskatchewan, Johnson has been chasing storms for 10 years at tornadohunter.com.