Transcript for This day in history: Feb. 26, 1993
Good evening here in New York tonight authorities are trying to determine what caused the explosion at the World Trade Center and investigators are looking into the possibility and it is only a possibility. That it was a bomb. Take a look at the scene now it's early evening here in New York City between the two buildings with the lights on of the 110 story towers which dominate the skyline. Of lower Manhattan all the power is off. On the ground tonight emergency crews from the fire the police and other investigative agencies are looking for the cause of the explosion and still in the dark going through the almost 100 floors looking to see if there are any peek at the scene earlier. More than a 100000 people either working in the building or visiting it on any given day. Having to grope their way down and out at least five people were killed and nearly 500. Injured our first full report is from ABC's Mort dean. The underground explosion was so powerful it rock even the top floors of one of the Twin Towers. 96 floors and we were sitting there doing my work and all of a sudden we heard a loud bang all the wasn't. Huge explosion that rocked. The building. Down darkened stairwells choke with soot and smoke thousands of workers broke their way to safety it was a frightening and exhausting experience. It's like to out of it down. People look at that now as horrible as live now look back. Stay away. Those who feared they would not make it down to the street instead escape to the top of the Twin Towers 110 stories above lower Manhattan. Some of them were evacuated by helicopter. Many were trapped in elevators or in their offices. And some punched holes through the building's thick glass facade to gulp fresh air or wave SOS signals. The blast be tipped the street like deadly tale. The roof of a commuter train station under the building collapsed the explosion occurred underground apparently in a multi story park. Finger. We are one floor below street level and what was paved parking garage that an example of the tremendous force of the explosion. Part of ripped apart. Morning floors of this garage at the last one on top of the hill. Being counted tremendous fire. We have partial collapse of it the floors inside the garage and we've got another victim we found in the garage worn him out. Federal officials have been called in to investigate the possibility that it was a bomb that caused the explosion. As more and more people were rushed to hospitals the rescue and search effort continues. The huge task of going door to door and office to office. While also locating and looking into the more than 200 elevators in the complex that stopped operating when the explosion occur. Morton dean ABC news New York.
This transcript has been automatically generated and may not be 100% accurate.