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WTC Plaza Map
Blast mitigators were placed conspicuously around the plaza for bomb technicians to find easily. The general public and Twin Tower occupants were likely not aware of the blast mitigator’s important function.

February 26, 1993

A Preface to September 11, 2001

On February 26, 1993 at approximately 12:18 pm, a bomb exploded in the second level of the North Tower's underground parking garage. The blast produced a crater that was about 150 feet in diameter and five floors deep. Six people were killed and more than one thousand were injured.

One response to the 1993 bombing was to install blast mitigators on the World Trade Center Plaza. These 600-pound containers were designed to assist if explosive devices were found nearby. Several were found among the material at the Fresh Kills recovery operation.

Fortunately, these mitigators were never used for their original purpose. If a bomb were found, it would be placed in the container in hopes of containing the possible blast. The mitigator would force the explosion upward instead of outward. Soon after their installation, the protocols for dealing with explosives changed and other practices were to be followed instead.

Bomb Technicians

Bomb technicians from several federal and state agencies assisted during the World Trade Center attacks. Among other activities that day, they searched vehicles along the adjoining streets for suspicious packages, determining whether hidden explosives might be involved.

Training for this dedicated and hazardous work comes from the Federal Bureau of Investigation’s Hazardous Devices School, which opened in 1971. The Port Authority’s police were given similar training on hazardous and explosive materials to ensure better protection of the World Trade Center after the 1993 bombing.

Explosive detection dogs work closely with the bomb technicians. For over a century, specially trained dogs have assisted with law enforcement. Today, they are especially valued for providing additional security for visiting dignitaries and at airports. Breeds such as German shepherds and Labrador retrievers are used for this highly trained work.