CALCASIEU PARISH, LA (KPLC) - It was felt through Calcasieu Parish, but officials say no one was hurt, and the public is safe.
Still many are left with questions.
Joe Andrepont with Westlake Chemical confirms Wednesday night's loud boom was caused by a process called "decomp" at its polymers facility.
Andrepont says it's been years since Lake Charles has had a decompression, but it happened so quickly even officials were taken by surprise.
What started as a typical Wednesday night quickly took a turn.
"I have a sister that lives in my neighborhood (and) her house shook, and I just didn't hear it," said Calcasieu Parish Sheriff, Tony Mancuso. "But I did (wake up) from the calls, and from talking to our patrol shift about what was going on."
While a few like Mancuso didn't hear the loud boom, many across the parish did.
"It caused a little stir with the public, and they have a right to know too what's going on in our community," he said.
Andrepont says it was a decompression process.
"Normally this takes from the process from a normal reaction to the completion of a fireball approximately five seconds," he said.
Andrepont explained that's what happened at their Polymers Unit, when a pressure inside a reactor increase to the point a safety disc breaks, allowing the ethylene gas to release and ignite - lighting up the sky, burning off in a short fire, and create a loud boom.
"Our safety devices were in place, our employees were safe, they're accounted for and they're okay," said Andrepont.
He says sound waves on Wednesday's cool, clear night traveled across Southwest Louisiana and could be heard in Southeast Texas.
Andrepont says the ethylene released is burned away by the ignition.
He says there's little notice when this emergency release is about to trigger, and the board operator doesn't have time to notify everyone.
He says with this rare occurrence, he understands the community's concerns.
"Certainly when you hear a loud boom and your windows rattle, you're wondering what's concerning," he said. "You know you think of something that's much more extreme."
And while Andrepont assures that everyone is safe and there is no danger to the public, he says they'll investigate and resume things as normal soon.
Andrepont says they finished their initial investigation Thursday and will be back to using that part of the facility Friday.
"We'll install a new pressure disc back into the reactor, get everything cleaned up and then will begin the process of starting the unit back up," he said.
Sgt. James Anderson with Louisiana State Police confirmed there is no danger to the public.