The Georgia Emergency Management Agency swung into operation immediately.

''Of course we're on high alert,'' said Kathy Huggins, spokeswoman for the agency. ''People have been training for this sort of thing, as much as possible. ... We live in an age when the impossible happens.''

Thursday and Friday, GEMA planned to hold another training session on terrorism and a mock airplane crash in Pooler, near Savannah.

The Georgia Bureau of Investigation, which also gained valuable anti-terrorism experience in the wake of the 1996 Centennial Park Olympic bombing, was on standby this morning morning to respond to any incidents in Georgia or help outside the state.

''Obviously, the events of today have been devastating,'' said GBI spokeswoman Vicki Metz. ''The GBI has agents assigned to a joint terrorism task force, and if anything would arise here in Georgia, we would work with the federal and other state agencies and provide our experience and expertise.''

Metz said that by about 11 a.m., the agency had no reason to believe there was a serious threat inside the state.

''We have received quite a few calls from concerned citizens,'' she said. ''Obviously, we will work with the Georgia Emergency Management Agency handling those calls. We are just keeping our ears and eyes open.''

Flights at the world's busiest airport, Hartsfield Atlanta International Airport were canceled.

In a news release, the airport said the Federal Aviation Administration had shut down all of the nation's airports. Passengers were advised to stay away from Hartsfield until further notice.

''We want to assure the public that their safety and security are our top priority,'' the release read. ''While we cannot publicly disclose current airport measures, we continue to employ multi-layered security system(s) to ensure the safety of all Hartsfield passengers and employees.''

Also in Atlanta, the Georgia National Guard locked down its Oglethorpe Armory, which is the National Guard headquarters, said Lt. Col. Ken Baldowski, a Guard spokesman. That is not an unusual measure for increased security, he said.

Also, Maj. Gen. David Poythress, the state adjutant general, issued a statement asking all National Guard personnel to move to a higher level of security and to use extreme caution. He also asked them to take measures to protect lives and property.

The National Guard and 3rd Infantry Division combined have more than 3,000 troops deployed to Bosnia and Kosovo. Those areas already have high security and no word was available on what the threat conditions were in those places.

The incident was the number one topic of conversation among Georgia lawmakers entering the Capitol this morning morning to continue the legislature's congressional redistricting session.

Some appeared visibly shaken by the news, as word of the latest developments passed up and down the halls.

During the devotional at the beginning of this morning's session, Rep. Allen Hamontree prayed to God to give America's leaders wisdom and guidance, bless rescuers attempts to save victims and stay the hands of terrorists.

''While this (redistricting) is important, we face deeper eternal issues that go beyond district lines and political futures,'' said Hamontree, R-Cohutta.

After the usual Pledge of Allegiance, the entire House stood and sang in unison, ''God Bless America,'' at the suggestion of House Majority Leader Larry Walker, of Perry.

Members held hands for a moment of silence for the victims at the suggestion of Rep. Gene Callaway, R-Lilburn.

''The events in New York City and Washington D.C. this morning have been tragic,'' Gov. Roy Barnes said in a written statement. ''Our thoughts and prayers go out to those who have been injured or have suffered any loss.

''This is a time for calm - not panic. Our emergency management officials are well-trained and are closely monitoring what is happening here in Georgia and throughout the nation.''

Security appeared normal at the Capitol as lawmakers arrived before 10 a.m. to continue the congressional redistricting session but by 10:30 police protection had been beefed up. Additional capitol police were stationed at each entrance where there is a metal detector.

Speaker Tom Murphy told legislators of the added security shortly just before 11 when the House adjourned for the day.

''There's been no threat to the capitol that we know of, but there is extra security around the capitol,'' he said.

University of Georgia President Michael Adams closed the 32,000-student university at noon ''in view of the national emergency,'' after he, faculty and administrators spent an anxious morning watching the horrific news.

Adams made the decision in consultation with three senior vice presidents and Athens-Clarke Mayor Doc Eldridge.

''The president was watching TV, like everyone else in the world, and realized that formal education was at an end,'' UGA Spokesman Tom Jackson said.

Before this morning, the deadliest act of terrorism on U.S. soil was the bombing of the Murrah Federal Building in Oklahoma City. Now, the attack that sent Timothy McVeigh to the death chamber ranks a distant second.

''That was 168 folks - it sort of pales in comparison to this,'' said William L. Waugh Jr., a professor of public administration and urban studies at Georgia State University.

Waugh, who specializes in international and domestic terrorism, said the apparent suicide bombings bear all the markings of violence from the Middle East.

''Suicide bombers are sort of unusual except in the Middle East,'' he said. ''That tends to point the finger in that direction.''

A religious extremist, like the infamous Osama Bin Laden, could be behind the attacks, he said.

''Religion is far more likely to have set this off than politics,'' Waugh said. ''When you're talking about terrorism events, the common wisdom is that people want a lot of people watching and not a lot of people dead.

''The only exception to that is religious groups. They tend to be more violent.''

The news had federal workers throughout the state shaken.

Employees in three Savannah federal office buildings engaged in their usual smoke breaks.

'Everybody is scared. We're in a federal building and that's what they're aiming at,'' said a woman on a cigarette break.

She hurried inside, saying she had a lot of work to do and could not give her name because she was a federal employee.

Morris News Service reporters Doug Gross, Dave Williams and Walter C. Jones contributed to this report.