Tom Kirkman was not in attendance, due to being selected as President Richmond's "designated survivor" for the high-profile event. Also not in attendance was Congresswoman Kimble Hookstraten, due to being selected as the GOP's designated survivor.
Tom Kirkman had originally given topic points for the speech, but they were scrapped the day of the address.
Peter MacLeish was the only survivor of this attack, because he was meant to be. He worked with the conspirators behind the attack and because he was a congressman, he needed to survive. So they built a bomb shelter for him to hide during the bombing.