United CEO Oscar Munoz has sent a letter to employees about the forced ejection of a passenger Sunday night that was caught on video and has led to outrage. Here's what the airline is claiming:

• The passenger in question was selected as part of United's procedures to make room for airline staff that needed to board.
• He "raised his voice and refused to comply," and each time they asked "he refused and became more and more disruptive and belligerent."
• Crew members "were left with no choice but to call Chicago Aviation Security Officers to assist in removing the customer from the flight," and the passenger, "continued to resist - running back onto the aircraft in defiance of both our crew and security officials."