White House's military department head Luis Caldera offered official apologies for the flight of the presidential aircraft Boeing 747 escorted by two fighter jets over Manhattan Monday. The Boeing flying at low altitude scared office workers who left their offices in panic. According to witnesses, it reminded the 9/11 events of 2001 when terrorists rammed into skyscrapers. The US air force and Federal Aviation Administration later announced that the plane flew over New York for photo shooting. Barack Obama was not aboard.