At about 15:40 EST, a flight attendant was seriously injured when she fell out of the main cabin door of a Boeing 737-300 at Newark International Airport. The airplane, which was operating as Continental Airlines flight 517, was parked at the gate. The airplane was completely closed and the jetway had been pushed back in preparation for departure. An agent asked if two additional passengers could board. The captain agreed to do so, and the agent proceeded back up the jetway to get the additional passengers. The captain then made an announcement over the public address system, after which a passenger came to the cockpit and advised him that the flight attendant had fallen from the airplane. According to a representative from Continental Airlines, the flight attendant could not remember how the fall occurred. At the time of the accident, the flight attendant had been with the company for four months.