Large low flying craft with clear bottom

I myself did not see the craft but everyone else in my immediate family saw it. My entire family agrees that the craft was very low flying and so large that they could not tell me what shape it was. My dad attempted to draw it for me but said it was difficult because he said that “looking in the craft was like looking at an airplane with no bottom. He claims that the bottom of the craft was completely clear and he could see seats. My family does not know for sure if they saw anyone but they feel like they did. A low hum or buzzing noise was heard as the craft passed over our house. My family promptly ran into the garage after they saw the craft. My mother seems to feel that the shape was triangular but the whole event is a bit fuzzy for her.
Witness indicates that the date of the sighting is approximate.  PD