By Bradley Graham and John Mintz
Washington Post Staff Writers
Friday, August 15, 2003; Page A11

In the first minutes after yesterday's power blackout, the Pentagon launched two Air Force F-16 fighter jets to patrol skies between New York and Washington, and put other military aircraft on alert at eastern U.S. bases, defense officials said.

But federal and regional authorities quickly determined that the electrical shutdown was not caused by a terrorist act and did not reflect a national security threat, the officials said.

The sudden paralyzing blow to a large section of the country provided the first test of the emergency response network set up after the Sept. 11, 2001, terrorist attacks. Initial accounts by some of the officials involved suggest that communications were quickly established among key military and intelligence centers, regional crisis centers and electric power industry executives.

Plugging into an elaborate conference call network were authorities at the White House, the Pentagon, the CIA, the FBI, the Department of Homeland Security and the Nuclear Regulatory Commission, in addition to other agencies.

U.S. intelligence officials, urgently scanning the latest information available from around the world, found no reports of heightened threat warnings overseas.

"It was pretty clear pretty quickly that the blackout was a power plant problem," said one military official who was in the Pentagon's operations center during the initial phase of the power outage.

While terrorism was ruled out, the Pentagon bolstered the country's air defenses as a precaution. The scrambling of the fighter jets recalled the constant combat air patrol missions that were initiated over major U.S. cities after the Sept. 11 attacks. Those flights gave way last year to occasional, random patrols, but with contingency plans by the North American Aerospace Defense command (NORAD) to resume more intense coverage if necessary.

"NORAD has no reason to believe there's an imminent airborne threat," a defense official said. But, he added, the decision was made to send the extra fighters aloft and put others on alert "as a precautionary measure." The planes took off from Andrews Air Force Base.

Said another military official: "We could have had more fighters airborne in five minutes."

Defense officials braced for the possibility that New York and other major cities left without power might request federal troops to maintain order and back up local police. Officials also prepared for possible appeals for generators, cots, medical equipment or other emergency assistance. But by last night, no such requests had come.

"We're closely monitoring the situation," said Michael Perini, spokesman for Northern Command, another post-9/11 creation, this one established to coordinate the military's response to domestic emergencies. "We're anticipating where we feel the military can help, from communications to medical services to setting up places where people could sleep."

"This is the first major incident to affect a part of the nation's critical infrastructure since the launch [in March] of the Department of Homeland Security, and we are responding," said Brian Roehrkasse, a department spokesman. "We're communicating with and working closely with the industry sector involved, which is how things are supposed to work."

Within moments of the start of the blackout, the department's command center at its headquarters in Northwest Washington contacted Consolidated Edison Inc. and other key electrical grid industry officials, using prearranged communications plans. "We immediately started receiving information from them in real time," he said. Within minutes, Homeland Security officials were notifying other government agencies that the problem likely stemmed from an electrical overload rather than an act of sabotage.

Homeland Security -- which now incorporates the Federal Emergency Management Agency -- also stood by with crisis teams, medical units and aircraft. But "no states have asked for any federal assistance," Roehrkasse said. "Backup generators are working, and states and localities are dealing with it."

Staff writer Dana Priest contributed to this report.