NBC - Three Chicago airport police officers yanked a man from his seat after a United Airlines flight was overbooked.
The man's head hit the arm rest and blood flowed from his mouth as he was pulled down the aisle.
Witnesses say the flight crew was trying to free up seats for United Airlines employees
The airline didn't get any volunteers, so its computers picked which passenger to kick off.
The backlash was so fierce that the airline's CEO responded by tweeting "I apologize for having to re-accommodate these customers. Our team is moving with a sense of urgency to work with the authorities and conduct our own detailed review of what happened."
The Department of Transportation is reviewing the incident.