Research news
Bitesized UFOs #054: Triangles over North Carolina, 1975
April 1975, Lumberton, North Carolina - on several nights during the first two weeks of the month, several sightings of V-shaped or delta-shaped objects were made by local law enforcement officers and civilians, plus researcher Lee Spiegel who had travelled to the area to get the story first hand. One made a "flat turn" before flying away. The objects were low, slow and made absolutely no sound at all. This was probably the first major group of sightings of triangular objects.
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https://www.youtube.com/watch?v=u2c0LyQFXJo