passage: Tuesday , September 11 , 2001 , dawned temperate and nearly cloudless in the eastern United States .
  Millions of men and women readied themselves for work .
  Some made their way to the Twin Towers , the signature structures of the World Trade Center complex in New York City .
  Others went to Arlington , Virginia , to the Pentagon .
  Across the Potomac River , the United States Congress was back in session .
  At the other end of Pennsylvania Avenue , people began to line up for a White House tour .
  In Sarasota , Florida , President George W. Bush went for an early morning run .
  For those heading to an airport , weather conditions could not have been better for a safe and pleasant journey .
  Among the travelers were Mohamed Atta and Abdul Aziz al Omari , who arrived at the airport in Portland , Maine .
  Boston : American 11 and United 175 .
  Atta and Omari boarded a 6:00 A.M. flight from Portland to Boston 's Logan International Airport .
  When he checked in for his flight to Boston , Atta was selected by a computerized prescreening system known as CAPPS ( Computer Assisted Passenger Prescreening System ) , created to identify passengers who should be subject to special security measures .
  Under security rules in place at the time , the only consequence of Atta 's selection by CAPPS was that his checked bags were held off the plane until it was confirmed that he had boarded the aircraft .
  This did not hinder Atta 's plans .
  Atta and Omari arrived in Boston at 6:45 .
  Seven minutes later , Atta apparently took a call from Marwan al Shehhi , a longtime colleague who was at another terminal at Logan Airport .
  They spoke for three minutes .
  It would be their final conversation .
query_and_answer: Who boarded a 6:00 A.M. flight from Portland to Boston 's Logan International Airport with Mohamad Atta and arrived at Boston at 6:45 pm ? || Omari
evidences: Atta and Omari boarded a 6:00 A.M. flight from Portland to Boston 's Logan International Airport . Atta and Omari arrived in Boston at 6:45 . Among the travelers were Mohamed Atta and Abdul Aziz al Omari , who arrived at the airport in Portland , Maine .