Black Triangle Sighting in Walpole, Massachusetts on June 30th 1984 – Triangle craft in the sky in East Walpole

It was just starting to become dusk outside, and I was sitting inside our apartment by our phone, looking out the window beside the stairs leading to the third floor of the building. We lived across the street from a city park with a church by one of it's entrances. It was still fairly light outside, enough to notice that there was a triangular shaped object hovering in the sky as I looked over the top of the church (though not directly over the church). It had red lights pulsating along the two edges that I could see from my vantage point (I could swear that they pulsed into blue-ish/green-ish, too, but they were mostly red). It hovered in place for probably 20-30 minutes, and then it ascended straight up at an incredible speed until it disappeared from my sight.