The fall of the twin towers decimated much of the communications infrastructure in downtown Manhattan. Debris from 7 World Trade Center, which collapsed at 5 p.m. the afternoon of September 11, fell against the area’s central telephone switching office belonging to Verizon, the local telephone company.

The basement at 140 West St. flooded with water from shattered pipes, rendering the backup power generators useless. Thus, many telephone lines were either damaged or deemed useless because they were connected to telephone switches without power. Failures of backup power also hit several other network facilities around downtown Manhattan.

The damage to the West St. central office affected about 200,000 voice lines for homes and small business, or about 10% of all Verizon lines in the city. But that doesn’t account for the 100,000 voice lines for large businesses and their data-capacity equivalent of about 3.5 million circuits. In addition, 10 cell-phone sites were destroyed, and AT&T was unable to continuously run its telephone-switching equipment in the nearby World Financial Center because of electric power interruptions.