WASHINGTON (AP) — Donald Trump is preparing for his first commemoration of the 9/11 attacks as president. The White House says Trump and first lady Melania Trump will observe a moment of silence Monday morning in remembrance of the nearly 3,000 people killed 16 years ago when hijackers flew commercial airplanes into New York's World Trade Center, the Pentagon and a field in Shanksville, Pennsylvania. The moment of silence is scheduled for about the time the first airplane struck one of the Twin Towers. Trump also plans to participate in a 9/11 observance at the Pentagon. Vice President Mike Pence will represent the administration at a ceremony at a memorial near Shanksville.