The spectacular scene unfolded about 7 p.m. on the north section of the four-lane Interstate 5 bridge near Mount Vernon, about 60 miles north of Seattle and 40 miles south of the Canada border.
On 27 December, 1972, Lieutenant-Colonel A T P Millen had noted that "the destruction" of Aghalane Bridge "suits us well in that it closes a route frequently used by Republic-based terrorists".