Loud, thunderous, rythmic noises for at least 60 minutes, followed by two lightless darkened low-flying helicopters headed toward it.

Witness1 left the bedroom. Witness2 was listening to music. Witness2 heard/felt what was thought to be a train going by, but it kept going and they took their headphones off. Witness2 then thought they heard thunder but it was continuous, and something was off about it. Witness2 went out to the living room and Witness1 was upset, having been hearing this strange noise outside as well. They go outside on the front porch, it’s a clear night, stars in the sky but there is thunder, but, it's rhythmic. near boom, far boom, near boom, far boom, and it goes on, getting progressively clearer until it is pretty obvious it's in the sky - but no lightning, no clouds, it goes on for another 20 minutes, and Witness2 steps inside to check on our daughter and goes back outside within a minute....as we are listening, there is the sudden sound of helicopter(s), and two lightless, dark, low-flying helicopters go by headed to the east really fast. there is some really loud booming, some high-pitched vibration feeling? Witness1 and Witness2 rush inside. We tell Witness3.
During this Witness2 kept trying to get their camera to work, but the application on the phone kept saying "camera not responding" so they recorded what audio they could with the voice recorder app. After they tell Witness3, and decide to go back outside, there is a dull buzzing in the air, and Witness1, Witness2, and Witness3 can still feel the rhythmic vibrations though there is nothing audible. The sound lasted probably a total of 1 hour. Witness3 and Witness2 were sitting on the front porch and Witness4 came out going for a walk and had heard the sounds as well. There was never anything to "see" from where we were aside from the two helicopters. It was felt and heard.
The sound was first noticed at 9:40PM CST, the first recording was made (video) at 9:53PM CST and then the camera application crashed and would not open again. There were a series of audio recordings made, however, the application continued to crash after about a minute to a minute and a half each time. The final audio recording that includes the last helicopter and the strange sound in the background was at 10:41PM CST.
Witness1 is 36, a parent, a student, and a volunteer in the community.
Witness2 is 39, a parent, a student, and works from home.
Witness3 is 55, a grandparent who works for the city.
Witness4 is in their 20’s, a very kind and friendly neighbor.