The New York Stock Exchange (NYSE) & Nasdaq shut down when America was attacked on September 11, 2001. The NYSE wouldn't reopen until September 17.
Former NYSE trader Kenny Polcari vividly remembers that day when retired Lt. Col. Rose-Ann Lynch sang 'God Bless America' standing alongside Hillary Clinton, NYC Mayor Rudy Giuliani and New York Governor George Pataki.
"9:15, on the morning of the September 17, they rang the bell once. A young woman, who was in the army, took up the podium and started singing 'God Bless America' completely alone, with no music," said Polcari. "Her voice was magical and it became very emotional."
Polcari said that everybody on the floor that day wondered "whether or not the system was going to hold up."
"...In any moment, you expect it to fail," Polcari said. "Because the market did exactly what you thought it would do. It came under immediate sell pressure."
The market underwent a selloff- one of the largest in the history of the exchange, plunging 7.1% in a single day.
Despite the market selloff, Polcari said that day was one of the most incredible days of his 40-year NYSE career because the "country stood up."
"You could feel every single person in the country just lock arms and stand up and said 'Okay, you kicked us in the stomach, and you knocked us down. Guess what, we just stood up and we are not getting knocked down again,'" Polcari said.