City of Gibraltar, MI
© Jessica McLean — Media News Group
A mysterious boom shook, rattled and rolled many residents of Gibraltar early Thursday afternoon.

The resonant sound was first mentioned by a resident who posted a comment on the Gibraltar Life Facebook group page, with numerous people saying they heard and felt it, as well.

Several people said it sounded like thunder, but the sun was shining brightly, with no storm clouds in sight.

One person said it felt like a minor earthquake, but none were reported.

Others surmised that the sound could have resulted from blasting at a nearby quarry. Many residents said the boom shook their entire house.

Gibraltar Police Chief Matthew Lawyer said he read the comments on social media, so he was aware of the boom, even though he didn't feel it himself.

While dozens of people posted about it on Facebook, ironically no one called the police to report it.

Lawyer said that the source of the sound has not been identified.