NEW YORK (AP) -- Planes crashed into the upper floors of both World Trade Center towers minutes apart Tuesday in a horrific scene of explosions and fires that left gaping holes in the 110-story building.
There was no immediate word on injuries or fatalities in the twin disasters, which happened shortly before 9 a.m. and then right around 9 a.m.
In Washington, officials said the FBI was investigating reports of a plane hijacking before the crashes.
The towers were struck by bombers in February 1993.
"The plane was coming in low and ... it looked like it hit at a slight angle," said Sean Murtagh, a CNN vice president, the network reported.
Large holes were visible in sides of the 110-story buildings, landmark twin towers.
"I was watching TV. and heard a sonic boom ...," witness Jeanne Yurman told CNN. "The side of the world trade center exploded. Debris is falling like leaflets. I hear ambulances. The northern tower seems to be on fire."
The tops of the twin towers were obscured by the smoke.
Thousands of pieces of what appeared to be office paper came drifting over Brooklyn, about three miles from the tower, one witness said.
The center bombing on Feb. 26, 1993, killing six people and injured more than 1,000 others.
In 1945, an Army Air Corps B-25, a twin-engine bomber, crashed into the 79th floor of the Empire State Building in dense fog.