Salem and Marblehead's latenight "mystery explosions" have become something of a local conversation piece.

Every couple of weeks, our Facebook and Twitter page will light up with messages from area residents who want to know what caused that earth-shattering sound in their neighborhood so late at night.

The latest report was in the early hours Saturday morning, when residents in both Marblehead and Salem called 911 to report hearing what sounded like a firework or gunshot in their neck of the woods.

A big thank you to Derek B, who sent in the video above, which he captured on home surveillance equipment.