<Anchor> In
the United States, aircraft operations were completely suspended for about 90 minutes, causing chaos.
It was the first time since the 9/11 attacks, and it is known that it was not a cyber attack, but because one computer network file was wrong.
This is Washington Correspondent Nam Seung-mo.
<Reporter>
Reagan National Airport, the gateway to Washington, DC, the capital of the United States.
Passengers are busy checking for flight delays or cancellations.
[Mike/Aircraft Delayed Passenger: At first they said it would be delayed by 30 minutes, then after a while they said it would be delayed by 60 minutes, and then they said the plane would take off at 3:00 PM.
] 'Notam' malfunctioned and there was a problem with aircraft operation.
The Federal Aviation Administration found a problem in the computer network at around 5:30 am yesterday (11th), but failed to solve it, and at 9:15 pm last night, all airports in the United States stopped operating aircraft for safety reasons.
Flights resumed within an hour and a half, but the aftermath of all aircraft operations being suspended for the first time since the September 11, 2001 terrorist attacks was significant.
It's been 4 hours since flights resumed, but as you can see now, there are still many disruptions to flights, such as delays or cancellations.
As more than 10,000 flights were delayed and 1,300 flights were canceled, stranded passengers were in great confusion.
Korean Air's three flights were also delayed by about an hour.
The Federal Aviation Administration said an initial investigation into the cause of the malfunction found one corrupted database file, but there was no evidence of a cyberattack.
The US authorities are planning to find the exact cause and prevent a recurrence, but it is evaluated that the vulnerability of the aging US aviation system has been revealed through this incident.
(Video coverage: Oh Jeong-sik, Video editing: Cho Moo-hwan)