What event prompted the U.S response known as Operation Noble Eagle?

The event that prompted the U.S. response known as Operation Noble Eagle was the September 11 attacks. Following the terrorist attacks on the World Trade Center and the Pentagon on September 11, 2001, the United States implemented Operation Noble Eagle as a direct response to enhance security and protect critical infrastructure and airspace within the country. This operation involved the deployment of military resources, including fighter jets, to monitor and secure the airspace, as well as the establishment of increased security measures at airports and other key locations.

The other events listed, while significant in their own contexts, did not specifically lead to Operation Noble Eagle. Hurricane Katrina was a natural disaster response, the invasion of Iraq was part of larger military operations tied to the War on Terror, and the bombing of Yugoslavia was related to NATO's involvement in the Balkans, none of which directly initiated Operation Noble Eagle.