FRESNO (CNN) -- Hours after the initial attacks of 9/11, two fighter pilots from the California Air National Guard 144th Fighter Wing intercepted a Bay Area-bound jetliner.
They had orders from NORAD to bring the plane down if they needed to.
All U.S. flights were grounded or diverted in the hours following the attacks of 9/11 20 years ago.
The Operations Group Commander of the 144th Fighter Wing in Fresno, Col. Rob Swertfager, didn't watch the disaster unfold on TV.
He said, "That morning, we really didn't know where the attack was originating from."
Swertfager sat in the cockpit of his F-16 fighter jet while crews loaded live ammunition.
Details of the mission were declassified five years after 9/11.
He recalled, "About 10 a.m. ... we got scrambled by NORAD to go intercept a Thailand Air 747 that was on an 8-10 hour journey from the Pacific."
Two F-16's left Fresno to investigate why the flight wouldn't divert to Canada or Mexico, as instructed by the FAA.
Swertfager said, "They weren't able to comply because they had a fuel shortage on board but we didn't know if that was factually correct or not."
He wondered if the plane was part of the attack on the U.S.
Just nine minutes after leaving the Central Valley, Swertfager and his flight lead rolled behind the 747 fifty miles off the coast of San Francisco.
He issued a very serious radio message to the flight crew, telling them, "Our nation is in an emergency and non-compliance will not end well for everybody."
NORAD instructed Lt. Col. Ron Manor to be prepared to use weapons on the airliner if needed.
Swertfager looked for signs of a highjacking -- drawn shades, scared passengers.
Instead, he saw smiling kids and adults.
"Luckily as I pulled alongside the aircraft, people were waving. Everything looked normal onboard."
The colonel made his observations while flying at 450 mph.
Swertfager said, "I pulled alongside the cockpit fairly close. Maybe within 10 feet of the cockpit."
There, he saw confused crew members. "They were all in uniform with their ties and their eyes were as big as saucers, wondering what was going on."
Swertfager told the pilots why they were being escorted in for a landing. The Thailand Air 747 was greeted at SFO by hundreds of first responders.
He said it was the only flight to land that day in Northern California after the attacks occurred.
Swertfager remembered, "It was probably the most stressful mission I have ever been on -- and that's after back-to-back summers coming back from Operation Southern Watch, where we were being shot at regularly."
Col. Swertfager has flown combat missions over Iraq but those 45 minutes airborne on 9/11 were unlike anything else he has experienced in his career.
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