On September 11th, 2001 , a hijacked airline slammed into the north tower of the World Trade Center at 8.45am; eighteen minutes later another hijacked plane struck the south tower. As thousands looked on in horror - in addition to millions more viewing on TV - the south tower collapsed at 9.50am, its twin about half an hour later. That afternoon, a smaller building in the World Trade Center complex also crumbled, and the center was reduced to a monument of steel, concrete and glass rubble.

The devastation was staggering. While most of the 50,000 working in the towers had been evacuated before the towers fell, many never made it out; hundreds of firemen, policemen and rescue workers who arrived on the scene when the planes struck were crushed when the buildings collapsed. In all, around 3000 perished in what was easily the largest attack on America in history.

In the days after the attack, downtown was basically shut down, and the seven-square-block vicinity immediately around the WTC - soon to be known as Ground Zero - was the obvious focus of the rescue effort. New Yorkers lined up to give blood and volunteer to help the rescue workers; vigils were held throughout the city, most notably in Union Square, which became peppered with all manner of candles and makeshift shrines; and all city hospitals were on red alert to receive injured victims. Precious few came, and as weeks passed, reality began to sink in. Through it all Mayor Giuliani cut a highly composed and reassuring figure as New Yorkers struggled to come to terms with the physical and emotional assault on their city. It was more than just sheer numbers - the lives lost, the expected $60 billion cost of insurance payouts, property value loss, cleanup (expected to take a full year) - things were irrevocably changed.

The chief suspect in the attacks was Osama bin Laden's many-headed terrorist network that he operated from the mountains of Afghanistan. In October 2001, the US government struck back against Afghanistan's ruling Taliban group, known to harbor and support bin Laden.

An observation platform , overlooking the site, has been erected on Broadway and Fulton Street.