President Trump has presided over his first 9-11 commemoration in office, marking the 16th anniversary of the attacks. He and first lady Melania observed a moment of silence at the White House and later at the Pentagon. Nearly 3,000 people died after hijackers crashed planes into New York's World Trade Center, the Pentagon and a rural Pennsylvania field in 2001. september11 911 neverforget wtc nyc pentagon shanksville trump