The Department of Homeland Security said early indications are that an airplane crash on Manhattan's Upper East Side is a terrible accident and not terrorism.
One witnesses said the thunder of the crash was accompanied by fiery debris raining on the street below. An apartment-dweller watching from a block away calls it "a mob scene with police and helicopters circling."
Even though the deadly crash -- and the sight and sound of first responders -- brought to mind the attacks on the World Trade Center five years ago, the FBI said there's no indication that the plane was flown intentionally into the 50-story building, although federal agents were sent to the scene as a precaution. The Pentagon also said it's taking no chances. Fighter jets have been scrambled over U.S. cities as a precaution.
New York Governor George Pataki told Fox News, he understands the heightened awareness, but he said residents should remain calm and have confidence that the government is doing everything possible to protect them.