A security officer and a sergeant with the Chicago Department of Aviation have been fired for violently dragging Dr. David Dao off of United Airlines Flight 3411 in April for refusing to give up his seat for a flight attendant. The incident was captured on a video that went viral, calling into question the protocols of airlines and transit law enforcement. Two other aviation officers received five-day suspensions for their role in the matter, one of whom resigned, according to a quarterly report from the Inspector General for the CDA, the Chicago Sun-Times reported Tuesday.