The Boeing-built air superiority fighters were launched out of Portland, Oregon, under the auspices of the North American Aerospace Defense Command (NORAD) to intercept the airliner around 4:00 Pacific time 10 April.
"The Korean airliner was intercepted, diverted and the aircraft was shadowed until it landed at Canadian Forces Base Comox [British Columbia] at approximately 5:30," a Pentagon spokesman says.
The F-15s were likely part of the Oregon Air National Guard's 142nd Fighter Wing, which performs the air sovereignty mission for NORAD and its parent US Northern Command organization.
CFB Comox sometimes serves as a temporary forward base for Canadian Forces CF-18 Hornets, which are also built by Boeing, but is primarily used by search and rescue and maritime patrol aircraft. Given that US aircraft were used for the intercept, it is unlikely that a CF-18 detachment is currently present at the base.
NORAD itself is a joint Canadian and US command that was established in 1958 to defend North American airspace from intruders and provide warning of a nuclear attack. At the time, the threat was primarily from Soviet bombers and ICBMs, but after the events of September 11, 2001, NORAD took on an expanded role in policing the skies against similar terrorist threats.