A loud boom was heard across New Orleans Tuesday night, an explosion that shook houses and sent NOLA residents to Facebook and other social media looking for its source.

But as of Thursday, city officials still say they have no idea what it was.

Loud Enough to Call the Cops

In fact, New Orleans Police confirm that the mysterious frightened so many in the city that the 911 emergency service received numerous calls. But authorities will only say that it remains under investigation.

Heard from One End of the City to the Other

A nola.com story says that residents in Algiers Point, the lakefront area, Marigny and Bywater, neighborhoods spanning the entire metro area, reported hearing what sounded like and explosion that shook their houses.

But At Least They Know What It's Not

NOLA police, though having no definitive information on what it was, are, nonetheless, willing to tell residents what it was not. Not a sonic boom, says nola.com, "Maneuvers are done deep over the Gulf of Mexico and usually aren't heard in populated areas.

How about an earthquake? Again, nola.com. "The US Geological Survey, which monitors earthquake data as part of the Department of the Interior, has no reports of earthquakes near New Orleans in the past day.

A meteor, maybe. Nope, says nola.com. "A meteor specialist at NASA said the loud boom does not appear to be caused by a fireball and report, 'nothing substantial over that area (Tuesday) night.'"

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