BLAST DAMAGE
The effects of the blast on the World Trade Center were severe.
PLAZA LEVEL (three levels above the explosion)
- A 100-square-foot section of concrete was cracked and lifted.
CONCOURSE LEVEL (two levels above the explosion)
- A 400-square-foot hole was opened in a meeting/dining room near the Liberty Ballroom of the Vista Hotel.
- Glass windows, the partition between the Vista Hotel and Tower 1 at the concourse level, were blown out from the explosion, creating a pathway for heavy smoke migration from the Vista Hotel to Tower 1.
- A section of plaster-and-lath ceiling above the hole collapsed.
- B-l LEVEL (one level above the explosion)
- A 5,000-square-foot hole was opened on the ramp leading to the parking garage below.
- The Port Authority command/ communications center was heavilydamaged and rendered inoperable.
- Walls and ceilings were heavilydamaged.
- Elevators were damaged.
Seven steel columns were damaged and left without lateral support.
B-2 LEVEL (ground zero)
- An L-shaped crater, approximately 130 by 150 feet at its maximum points, was opened, collapsing reinforced concrete and debris onto levels below.
- At least nine steel columns were heavily damaged and left without lateral support.
- Many walls collapsed, including a concrete block wall adjacent to the blast area that collapsed onto and killed five WTC personnel.
- Doors/enclosure walls of Tower 1 elevator shafts were heavily damaged.
- Some 200 vehicles were fully or partially destroyed, and many were on fire.
- Primary’ electrical power feeder lines were damaged.
- Stairway doors and shaft walls were heavily damaged.
- Some standpipes were damaged.
- The sprinkler system in the immediate blast area was destroyed.
B-3, B-4, B-5, B-6 LEVELS (below the explosion)
- Debris from the blast traveled through a three-level architectural opening (spanning B 3 through B 5) and crashed down on refrigeration equipment on B 5.
- A ceiling of the PATH train station on the B-5 level collapsed.
- A 24-inch-diameter water supply pipe from the Hudson River to the air-conditioning chillers, as well as other smaller refrigeration/air-conditioning and domestic water pipes, were ruptured.
- Domestic water lines to the emergency generators were damaged on the B-6 level.
