What was established to address the ATC system's shortcomings in notifying radar and tower facilities of hijackings during the 9/11 attack?

The Domestic Event Network was specifically developed to enhance communication and coordination among air traffic control and other emergency responders in the event of domestic incidents, such as hijackings. It was established in response to the deficiencies exposed during the 9/11 attacks, where timely and effective communication was crucial for managing the crisis and protecting the safety of pilots, passengers, and the general public.

This network allows for the rapid sharing of critical information and situational awareness among multiple agencies, ensuring that both the radar and tower facilities are promptly informed about any potential threats or ongoing incidents. The ability to relay information quickly and efficiently is essential for effective decision-making and operational responses during emergencies, which was highlighted as a key area for improvement after the events of September 11, 2001.

In contrast, the other options, while related to security and emergency response, do not specifically address the needs of the ATC system in the context of hijackings and would not have been established with the same direct focus on enhancing communication for air traffic control during such events.