Amateur video footage:

A tornado unleashed a "war zone" of destruction, destroying homes and an emergency services building as a line of storms killed at least seven people in Ohio and damaged a swath of central Illinois.

Storms collapsed a movie theater roof in Downstate Elmwood and ripped siding off a building at a Michigan nuclear plant, forcing a shutdown. But most of the worst was reserved for a 100-yard-wide, 7-mile-long strip southeast of Toledo now littered with wrecked vehicles, splintered wood and family possessions.

The tornado ripped the roof and back wall off a gymnasium in Lake Township, Ohio, about 11 p.m. Saturday, several hours before a graduation ceremony was supposed to begin there. One of those killed was the father of the class valedictorian, whose home was destroyed. At least 50 homes were destroyed and another 50 severely damaged.

In Illinois, no deaths were reported, but the National Weather Service confirmed reports of a tornado touching down four times late Saturday.

Residents in Livingston, Kankakee, LaSalle, Peoria and Putnam counties reported heavily damaged homes, downed trees and broken gas lines. Among the hardest hit were the communities of Dwight, Elmwood and Streator, where 50 people were treated for injuries, including 17 who were taken to an area hospital Saturday evening.

"It's fortunate no one lost their life," Streator Mayor Jim Lansford said.

Source: Associated Press