President Bush was concluding a meeting of his National Security Council in the secure White House situation room when a military aide slipped him a chilling note: An American Airlines jet had crashed eight minutes earlier in New York.
With that 9:25 a.m. notice, a federal government on high alert for new terrorist acts sprang into action.
The president summoned his new homeland security director, former Pennsylvania Gov. Tom Ridge, to the situation room, a basement command center that is behind electronic-lock doors and guarded by uniformed Secret Service agents.
Ridge presided over a conference call with Attorney General John Ashcroft, FBI director Robert Mueller, Transportation Secretary Norman Mineta and Federal Emergency Management Agency director Joe Allbaugh. Military leaders and the Federal Aviation Administration also were on the call, shaping the government's early response to the tragedy.
A high-stakes question was at the heart of the debate: Did terrorism cut short Flight 587's journey to the Dominican Republic?
The president and his advisers briefly considered shutting down the aviation system, an unprecedented act ordered in the chaotic hours after four jetliners were hijacked Sept. 11 and steered into the World Trade Center towers and the Pentagon. Monday, they decided it was sufficient to close the New York region's three airports.
National Transportation Safety Board investigators already in New York raced to the crash site near John F. Kennedy International Airport. And NTSB officials in Washington quickly dispatched a go-team. Allbaugh, the FEMA director, headed to New York, where his crews were already in position. And FBI agents, already juggling the Sept. 11 and anthrax investigations, fanned out to determine if the plane was brought down by a criminal act.
Shortly after 10 a.m., Bush called New York Mayor Rudolph Giuliani and Gov. George Pataki to discuss the federal mobilization for a city still struggling to regain a sense of normalcy.
"It is heartbreaking to have to pick up the phone and call my friend Rudy Giuliani and Gov. George Pataki and once again express our condolences and at the same time assure the people of New York our federal government will respond as quickly as possible," Bush said later Monday.
In a sign of the extraordinary change that has occurred since the September terrorist attacks, Giuliani said he asked the president for air cover to protect his city.
Planes already were crisscrossing New York's airspace as has been their practice since Sept. 11, White House spokesman Ari Fleischer and Pentagon officials said. The Associated Press reported that additional fighters supplemented those patrols. The flights were dropped after several hours.
Early indications from intelligence, law enforcement and aviation agencies suggested a mechanical cause. An early all clear went out, however, when Ridge left the situation room and returned to his West Wing office at 11:30 a.m.
Administration and law enforcement officials acknowledged their deliberations and actions Monday were shaped by the Sept. 11 terrorist attacks.
On a day when most federal employees were on vacation to honor Veterans Day, the FBI director headed to the Strategic Information and Operations Center at FBI headquarters to monitor crash developments.
"In normal situations, if there is such a thing, I don't think the director would go to SIOC about a plane crash," said FBI spokeswoman Jill Stillman.
_ Information from the Associated Press was used in this report.