Early warning systems first suggested North Korean missile could hit US

In the minutes after North Korea launched a ballistic missile around 7:30 a.m. local time on Tuesday, the US command responsible for protecting the American homeland from airborne threats raced to determine whether the missile might be capable of striking the United States -- and for a moment, took steps as if it was.

source https://www.cnn.com/2022/01/13/politics/north-korean-missile-faa-grounded-planes/index.html