Air traffic controllers across the western United States on Monday grounded all planes minutes after North Korea launched a missile.
North Korea at 7:27 a.m. local time fired what was likely a single ballistic missile, according to South Korean officials.
A few minutes later, at 2:30 p.m. Pacific Standard Time, controllers at West Coast airports ordered a "ground stop," which forces all planes flying nearby to land and halts all planes on the tarmacs from taking off. The stop lasted for about seven minutes.
The missile landed in the water off the North Korean coast.
Which agency ordered the ground stop remains a mystery. North American Aerospace Defense Command spokeswoman Pamela Kunze told CNN on Tuesday that the order was not national and that a regional air traffic control facility might have issued the ground stop.
That statement contradicts what airport officials and pilots heard at the time, sources reported.
San Diego International Airport spokeswoman Sabrina LoPiccolo told Newsweek that air traffic controllers informed airport officials of a national ground stop order at about 2:30 p.m.
"We really don't have any more details," LoPiccolo said.
CNN reported that an air traffic controller cited "a national ground stop" in ordering a Cessna pilot to land.
Some air traffic controllers took to Reddit to express confusion, with one poster saying, "We haven't had a nationwide (or even multi-regional) [ground stop] since 9/11."
The Federal Aviation Administration, which has the power to issue a ground stop, did not respond to media sources' requests for comment.
The North Korean missile launch is the second the Communist dictatorship has made in a week. North Korean leader Kim Jong Un this month called for "bolstering the national defense," likely through building missiles, NBC reported. Kim, who is dealing with an economy crippled by U.S. sanctions and the coronavirus pandemic, has refused to return to peace talks with the United States.