A National Weather Service team says an EF2 tornado touched down near Savanna, Illinois, just before 7 p.m. Wednesday, June 12, 2013.
It carved a six mile path that reached about a half-mile wide.
Severe weather destroyed one house, injured a resident and knocked out power across the region.
Investigators say that wind speed reached up to 135 miles-per-hour.
It's just hours after Terry Koser spots a tornado on a path to his property.
"I've never seen anything like that with the three tails," he recalled.
He helps meteorologist Donna Dubberke search for answers.
"Nobody got hurt," he said.
"How many people were there at the time?" she asked.
"Just me," he responded.
Dubberke is a real storm detective. This National Weather Service team is checking for clues and documenting damage.
"The damage track is a classic tornado track with damage pointing toward itself or towards the path of the storm," she said. "And that's a classic indicator of a tornado."
Images from Wednesday night detail the storms. One tornado rolling through this house, injuring a resident and knocking out power before moving on.
"We'll go back and look at that to get kind of an estimate of the wind speed and strength," she said.
The fast-moving tornado lifted the roof off Koser's shed and tossed it about 100 yards. Seconds later, it was over.
"The roof on the shop is gone," he said. "We had some damage on the house."
Family members are loading branches and debris Thursday morning. There's a chilly reception as they fish items out of the pool. This storm tossing trees right out of the roots.
"We've got everybody here taking all day to clean up what happened in ten seconds," he said.
Through it all, Koser is safe. Despite the mess, it's a lucky break.
"Fortunate nobody was hurt?" I asked.
"That's the whole thing," he responded. "We can rebuild this stuff."
Fast moving moments they'll never forget.
A minor tornado also touched down briefly near Hanover without any significant damage. It's ranked as an EF0.