Few understand what Ground Zero looked like in the days and weeks that followed.
This footage captures the site on the night of September 11 and in the days immediately following the attacks, as smoke continued to rise from the massive pile of debris.
The fires at Ground Zero did not end on September 11. Deep beneath the rubble of the World Trade Center, they continued to burn intensely for nearly 100 days, with hot spots still being detected into December 2001.
During that time, firefighters, construction workers, engineers, and recovery crews worked around the clock in hazardous conditions. As smoke and heat continued to emerge from the ruins, they searched for survivors, recovered victims, and undertook the enormous task of clearing the site.