UPDATE:At least 9 dead in enormous outbreak of tornadoes
JEFFERSON COUNTY, Ind. -- A powerful severe storm system moved across the United States on Friday, with a slew of apparent tornadoes from Alabama to Indiana contributing to at least nine deaths and threatening even more destruction as the day wears on.
National Weather Service meteorologist John Gordon reported Friday afternoon the agency has about "half a dozen reports of tornadoes on the ground," as well as reports of "significant damage" -- stressing all the while that the worst may still be to come.
"This is an enormous outbreak that's going on right now across Kentucky and the South," Gordon said. "It's crazy. It's just nuts right here."
Tornadoes kill 6, leave miles of flattened towns and devastation across southern Indiana
HENRYVILLE, Ind. — Authorities say at least six people have been killed by tornadoes that ripped through a wide area of southern Indiana.
Spokesman Jet Quillen of the state Joint Information Center says three people died in Jefferson County and three were killed in Scott County as storms battered the state Friday.
Southern Indiana was particularly hard hit, with Indiana Department of Homeland Security spokesman John Erickson saying three had died in Jefferson County as a result.
In addition, Emergency Management Director Leslie Cavanaugh of Clark County -- which has about 110,000 people -- reported one death. An earlier fatality in the county was reported by Sheriff's Department Maj. Chuck Adams. The coroner was called in to determine a cause of death.
"We've got total devastation in the north-central part of the county (and) widespread damage from the west to the east," added Adams. "We are inundated with calls."
Cavanaugh also said that the local high school, Henryville Junior-Senior High School, had been "demolished."
According to Sara Reschar, an administrative assistant for the West Clark Community Schools, "students were already out of the school when the storm hit" -- having been dismissed about 15 minutes earlier.
Aerial footage from CNN affiliate WLKY showed structures torn to shreds and large swaths of trees knocked down in Henryville, about 20 miles north of Louisville, Kentucky.
Other aerial images showed similar devastation in St. Paul, Indiana. Several officials -- including Jeffersonville, Indiana, Mayor Mike Moore and U.S. Sen. Dan Coats -- indicated that the town of Marysville suffered especially significant damage.
The devastation was caused by a potent and widespread system that has spawned several tornadoes, according to the National Weather Service -- including two twisters that touched down in northeast Alabama and at least one in Indiana's Posey County at approximately 1:43 p.m. CT (2:43 p.m. ET).
About four hours later, Indiana Gov. Mitch Daniels said crews "are racing the nightfall" to assess the damage and help those in need.
"I am constantly amazed by both the unpredictability and the ferocity that Mother Nature can unleash, when she chooses to," Daniels said of the severe weather.
His counterpart in Kentucky, Gov. Steve Beshear, on Friday declared a statewide emergency to facilitate local authorities' access to state resources.
"We have reports of heavy damage in some areas of the state already, but the storm system has not cleared Kentucky yet," Beshear said in a statement. "By declaring a state of emergency now for the entire state, we can deploy any needed state assistance, such as National Guard troops, without delay."
Shawn Harley, from the National Weather Service, confirmed that people were trapped in damaged buildings after a large tornado struck the small town of West Liberty, Kentucky. There was no immediate word on casualties as a result.
In Tennessee, severe weather was responsible for critical injuries of as many as eight people in the cities of Harrison and Oolteweh, officials there said.
The storm brought golf-ball-size hail, strong winds and rain into the two northeast Alabama counties before continuing on a northeastward path into Tennessee.
Tennessee Emergency Management spokesman Jeremy Heidt said there were reports of possible tornado touchdowns in nine counties total. Damage assessment teams are "taking cover until the storms pass," though it is known that about 1,000 gallons of petroleum fuel spilled at a marina that was affected in the eastern part of the state.
"It's going to be a long night," Heidt said.
Between 40 and 50 homes in Hamilton County, Tennessee, have "significant damage that we know about," the county's Chief of Emergency Management Bill Tittle told CNN.
Reporting from that area near Chattanooga, CNN's Rob Marciano observed a continuous stretch of damage about 200 yards wide that ripped what had been brick-and-mortar homes down to their foundations.
Tittle said that there are 24 reported injuries and, while none of them appears to be life-threatening, he acknowledged that "we have not reached all the homes."
"We obviously have lots of debris, homes with roof damage, streets that are impassable that we have crews cutting down trees with chainsaws in order to get emergency vehicles through, and as of now our crews are just going door-to-door on foot," said Amy Maxwell, Hamilton County, Tennessee, emergency management spokeswoman.
Maxwell later said six to 10 people were at local hospitals after suffering injuries, and a triage area was set up at Ooltewah High School to treat patients on the scene.
Hamilton County Mayor Jim Coppinger said a touchdown of a tornado had been confirmed, though he expressed optimism that sound preparation and safety measures appeared thus far to prevent any deaths.
"We're just working diligently at this hour to try to make sure that everyone is accounted for," Coppinger told CNN. "And hopefully we'll be able to escape (without fatalities)."
Meanwhile, Alabama Gov. Robert Bentley said there have been seven injuries and about 40 homes destroyed but no fatalities after two tornadoes touched down in his state Friday morning.
"The April 27 tornado and the track of the two this morning were exactly the same," Bentley told CNN, referring to last year's twisters that left at least 238 dead. Both Buckhorn High School in Madison County and the Limestone County Correctional Facility in an adjacent Alabama county were hit Friday. There was also widespread damage in Madison County, the National Weather Service said, and some injuries were reported, according to a local ambulance service.
The Madison County Emergency Management Agency confirmed that a rain-wrapped tornado was spotted near the Harvest area, just northwest of Huntsville, which itself was hit hard by a tornado last year.
"The key thing that let me know it was serious was the loud wind," said Hovet Dixon of Harvey, Alabama. "It almost seemed like it was trying to lift my roof off.
The warden for the Limestone Correctional Facility, Dorothy Goode, said the prison was hit by the storm. All prisoners -- the facility holds about 2,200 -- were accounted for, she said.
Storms are expected to begin to weaken during the late evening as they move east toward the Appalachians. The severe weather threat should diminish overnight Friday into Saturday morning, Morris said.
These tornadoes follow an earlier outbreak that began Tuesday night and left 13 dead across Kansas, Missouri, Illinois and Tennessee and battered parts of Kentucky.
CNN's Susan Candiotti, Nick Valencia, Carma Hassan, Moni Basu, John Murgatroyd, Melanie Whitley, Joe Sterling, Dave Alsup, Logan Burruss, Kara Devlin, Joe Sutton and Phil Gast contributed to this report.