ARLINGTON, Va., April 29, 2011 -- About 3,000 National Guard members were responding to weather-related domestic disasters in 11 states on Friday, many in tornado-ravaged Alabama, while hundreds still tackled rising waters in North Dakota, the epicenter of flooding now challenging seven states.

In Alabama, Arkansas and Mississippi, tornadoes killed and injured people and destroyed property; in Texas, drought fueled wildland fires; in Illinois, Indiana, Kentucky, Minnesota, Missouri, North Dakota and Tennessee, swollen rivers either escaped their banks or threatened to do so.

The rash of domestic weather-related responses seemed unlikely to abate any time soon: Officials are watching the Mississippi River and Mississippi Gov. Haley Barbour warned of potential major flooding.

More than 300 people are dead after more than 160 tornadoes swept through seven Southern states midweek in the worst natural disaster to hit the nation since Hurricane Katrina.

Thousands of people were injured, many more rendered homeless and at one point at least 1 million people were without power after the tornado swarm inflicted damages estimated in the billions of dollars, according to news reports.

It was the deadliest tornado swarm since 310 people were killed in 1974.

About 1,100 Guard members were on duty in Alabama today, and the governor has authorized up to 2,000. President Barack Obama, who on Friday declared a major disaster in Alabama, was visiting damaged areas today. Guard missions included search and rescue, security, transportation and road clearing, National Guard Bureau officials reported.

The National Weather Service today reported that it rated one 205-mph, half-mile-wide tornado that struck Mississippi on Wednesday that state's first EF-5 tornado since 1966 and predicted more of the tornadoes that struck the South will receive the same damage rating -- the highest.

About 40 Guard members were providing traffic control points, security assistance and communications support in Mississippi.

More than 50 Airmen were among the 72 Guard members helping Arkansas residents recovering from tornado damage, providing security, patrolling roads, delivering water and performing search and rescue functions.

"We're doing all of this while we're also deploying Airmen to support the overseas war effort, while our day-to-day mission continues uninterrupted," said Air Force Col. Jim Summers, 189th Airlift Wing commander.

"This is a prime example of how flexible our Air National Guard is, but it takes the support of employers and a Guardsman's family for it to continue to work. I can't say enough about how employers and families have stepped up."

A handful of Tennessee Guard members were providing aerial damage reconnaissance. In that state, Guard officials said the tornadoes had contributed to Mississippi River flooding. Tennessee Air National Guard aircraft were damaged by hail and wind Thursday, Guard officials reported.

High Red River levels affected North Dakota, where some Guard members have been on duty for more than three weeks and 311 remained on duty today.

North Dakota Guard quick reaction forces placed thousands of sandbags to protect homes. Guard members also patrolled dikes and staffed traffic control points.

Working with the Guard "has been nothing but positive," Rick Schock, a city contractor, told a North Dakota Guard member. "They've been a great assistance to us."

Some 680 Guard members were on duty in Missouri, including 563 sandbagging, monitoring levees and roads, assisting evacuees and supporting law enforcement and 115 responding to damage that hit especially close to Guard members: An estimated $10 million or more in tornado damage to Missouri Air National Guard facilities at Lambert-St. Louis International Airport.

About 377 Illinois Guard members were assisting civilian authorities with route reconnaissance, levee surveillance, water deliveries and maintenance.

"In addition to their military responsibilities, our Soldiers and Airmen are also committed to their careers and families, so I am impressed with their rapid response to the governor's call," said Maj. Gen. William Enyart, Illinois' adjutant general.

Another 213 were on duty in flood-related operations in Indiana and 15 in Minnesota.

About 128 Kentucky Guard members tackled Ohio River flooding -- building barriers, filling sandbags and supporting civilian law enforcement authorities.

"I want to express my appreciation for what the Guard does," farmer Mike Gustafson told a North Dakota Guard member. "The effort makes it comfortable for people who are dealing with the stress and the issues that could result from a catastrophic problem.

"It's sometimes so easy to take for granted what they do, not only throughout the world for security, freedom of the lifestyle we live, but those things they do at the community level and the presence of them here is extremely appreciated."