NEW YORK -- A huge bomb explosion rocked the World Trade Center yesterday, killing at least seven people, injuring more than 600 and plunging the world's second-tallest skyscrapers into an urban hell of falling rubble and thick black smoke.
Thousands of workers staggered down smoke-filled, pitch-black stairways from as high as 107 stories for hours after the explosion at 12:18 p.m., while six others -- including a pregnant woman -- were plucked from the roof by a police helicopter.
"There was fire all around us -- it was like the 'Night of the Living Dead,' " said Bill Demic, a firefighter who was one of the first to respond. "We didn't think we would see anything alive."
Thousands more were trapped and waited hours to be led from the smoke-filled floors to safety. Power to the elevators was cut off by Con Edison, officials said.
FBI sources said that between 500 and 1,000 pounds of plastic explosive -- believed to be C-4, a putty-like substance considered the most powerful non-nuclear explosive, was packed into a van parked in the garage under the Vista Hotel and Trade Center towers. Two smaller bombs were believed to have been placed near the garage door and against a wall adjacent to the PATH station.
The main explosion created a 100-by-200-foot crater that caused concrete and debris to crumble through five floors below, law enforcement sources said. The smaller simultaneous explosions twisted the heavy metal garage doors and caused a ceiling to collapse in the PATH station.
New York Gov. Mario M. Cuomo said the main blast at the World Trade Center was the result of a bomb. "The information I have is it was definitely a bomb," said Governor Cuomo, who called in to the Cable News Network show, "Larry King Live."
But the investigation was hampered by concerns over the presence of hazardous asbestos, security sources said. "There is a huge asbestos problem . . . which prevents people from going in," an official said.
Special hazardous disposal experts were flown in from as far away as Chicago to help deal with the cancer-causing fibers that may have been sent into the air by the blast.
The official word from Police Commissioner Raymond Kelly last night was that "we have not determined the origin of the explosion." But sources said the explosions were caused by bombs, and said law-enforcement authorities were investigating whether a Serbian group protesting the planned U.N. airdrop of food to war-torn Bosnia was responsible.
