<span style="color: #222222;">Americans are commemorating the 19th Anniversary of the September 11 attacks with tributes that have been altered by Coronavirus precautions and woven into the Presidential campaign. <br />''<br />''The observance will be restricted so that not even victims' families can attend, though small groups can visit the memorial there later in the day. According to White House, President Donald Trump will pay respects in the morning at the Flight 93 National Memorial near Shanksville in Pennsylvania. Democratic challenger Joe Biden to pay respects in the afternoon at the same venue after attending the observance at the 9/11 memorial plaza at the World Trade Centre in New York.    <br />''<br />''The hijacked plane attacks on September 11, 2001 killed nearly 3,000 people at the trade centre, at the Pentagon and near Shanksville in Pennsylvania.</span><br />