Completed in 1973, the World Trade Center stood at 110 stories each, accommodating 50,000 workers and 200,000 daily visitors. The center was considered the hub of the Financial District. This district was the top tourist attraction and symbol of New York City’s progress. The Port Authority envisioned that the trade center would replace the Empire State Building, as the world’s tallest building; construction began in February 1967. Soon, World Trade Center revenues significantly jumped which made the way for major businesses. However, the World Trade Center was subject to attacks. On February 26, 1993, a bomb exploded in the parking garage of the north center. Equaling 2,200 pounds of TNT, the blast killed six people and injured 1,000 others. Six Islamic extremists were tried and convicted in connection with the plot. On September 11, 2001, two planes hit the World Trade Center towers causing devastating damage. The damage of each impact forced the physical weight of the towers to be redistributed. The damage of the lower floors resulted in the towers to give way.