Associated Press Sam Linton III, left, visits Ron Johnson outside his destroyed home in downtown La Plata, Md., yesterday. Johnson, who lived in the home since 1954, survived the tornado, which touched down Sunday night, by hiding under a work table in his garage. The tornado ripped through southern Maryland, killing at least three people and injuring nearly 100, shearing off homes at their foundations and snapping off treetops.

LA PLATA, Md. ÷ Tornado-ravaged cities from Missouri to Maryland picked up the pieces yesterday after an unusually wide and potent swath of thunderstorms plowed across the eastern half of the nation, killing at least six people.

Maryland was hit especially hard Sunday evening, with a tornado causing at least three deaths and 93 injuries in two counties south of the nationâs capital. A twister caused serious damage to at least a 10-mile stretch of this town of about 6,500 ÷ even leveling part of a school.

ăTheyâre banged up and shocked, and theyâre frightened,ä Civista Medical Center chief executive Chris Stefanides said of the injured. ăI donât think theyâve ever really seen anything like this before.ä

Maryland Gov. Parris Glendening issued a disaster declaration yesterday for Charles and Calvert counties, allowing the National Guard to send troops to the area.

Jack Cahalan, a spokesman with the Maryland Emergency Management Administration, said yesterday that 12 people were critically injured and 81 others had minor to serious injuries.

One of those killed was 74-year-old Margaret Albey of Prince Frederick. Her husband, George, was critically injured, said Calvert County sheriffâs Sgt. Rick Thomas.

ăThe house is gone,ä Thomas said of the Albeysâ home. ăItâs moved probably 80 yards down and into a ravine. They were in the house and trapped in the rubble.ä

A curfew was set in La Plata to keep people off the streets, and all public schools in Charles County were closed, officials said. About 6,500 customers in the area were without power early yesterday.

Thunderstorms struck states throughout the Tennessee and Ohio valleys on Sunday before continuing east to Maryland. The northern edge of the system brought heavy snow to Wisconsin and Minnesota.

In Missouri, a tornado packing wind of up to 180 mph and roughly two football fields wide plowed through the small town of Marble Hill, hurling a 12-year-old boy 50 yards to his death. At least 16 people were injured and several homes were destroyed.

ăIt took several houses completely away. Blown to sticks ÷ nothing left but the subfloor,ä Marble Hill Police Sgt. Dennis Willis said.

The boy, Billy Hoover, was on a sleepover with friends when the tornado touched down. Two of his friends in the house walked away, as did two other occupants, but the house was left in ruins, Bollinger County Sheriff Terry Wiseman said.

ăThat was my first tornado, and if I donât see another one, thatâd be fine,ä said Bollinger County Sheriff coroner Charles Hutchings.

The tornado also tossed vehicles, razed buildings and twisted tractor-trailers before the storms raced eastward.

At least 30 people were injured in Providence and Irvington, Ky., where Billy Garrett, 52, died when he was thrown about 200 feet from his mobile home, said Breckinridge County Coroner Bob Rhodes.

Dozens were injured in southern Illinois, and a 69-year-old woman was found dead outside her home in the town of Dongola. In nearby Cypress, two second-floor classrooms of the brick Cypress Grade School were missing a roof and walls.

The tiny town of Tobinsport sustained the heaviest storm damage in Indiana. A dozen people were injured and 10 of the 30 homes in the unincorporated community 60 miles east of Evansville were destroyed.