Mount Holly neighbors want to know what was behind a sound that was so loud, it shook houses and left windows rattling throughout town Tuesday night.

Mount Holly police received roughly 30 911 calls between 8 p.m. and 10:30 p.m., reporting a loud “sonic boom” type noise.

One woman who spoke with Channel 9 said the sound was so loud it rattled her windows, and she was certain that someone had hit her car parked on the street in front of her house. Another man said he thought there was an explosion at the plant a block away from his house.

Another woman who called dispatchers to report the noise said, “We just had an explosion…It sounded like we were in downtown Fallujah.”

"Oh my goodness, I thought I heard that here," a dispatcher responded.

(Click PLAY to hear 911 call)

"All the neighbors are outside right now. We all heard it," one caller told dispatch.

Big trucks and trains often roar through the area.

But Brian Greene was baffled about Tuesday’s boom.

"No, it's not a common noise," Greene said.

Greene thought it was an explosion from a plant about a block from his house.

Tuesday’s incident was not the first time something like this has happened recently, as residents reported hearing a similar noise Saturday night.

Police are looking into what may have caused the boom, but so far have no solid answers.

"The main thing is everybody is safe and that there is nothing to be worried about," Mount Holly Police Department Chief Don Roper said.

(Click PLAY watch Facebook live update from reporter Ken Lemon)

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