A laid-back weekend brunch at Los Angeles’ famously celeb-friendly Chateau Marmont reportedly turned into a full-on “duck and cover” moment when parts of the roof started coming down near diners during high winds.

Witnesses said the chaos unfolded in the hotel’s outdoor dining area as slate from the roof suddenly dropped just feet from a table of three. Staff rushed over to check what happened — but the scares weren’t done.

Minutes later, a massive bang reportedly echoed through the courtyard when an roughly 8-foot section of guttering came loose and slammed down onto a heater. In a split-second move, one guest jumped up and held the gutter in place to keep it from falling onto a nearby diner, according to accounts from people who were there.

“It was chaos,” a witness told the New York Post. “Bits of the roof suddenly started falling and we all started quickly trying to finish our food and get out.”

Staffers appeared stunned at first, witnesses said, but then quickly moved guests away from the area closest to the building and cordoned off nearby tables. One worker was reportedly overheard muttering, “What the f–k is happening?”

And because apparently the universe wanted to add extra sound effects, later in the day a bartender reportedly knocked multiple glasses off the counter, creating another loud crash behind the bar.

As if falling roof pieces and shattering glass weren’t enough, witnesses also described helicopters circling overhead and fire engines racing past while smoke rose from a hillside blaze in the Laurel Canyon area.

Adding a celebrity snapshot to the scene, “Borat” star Sacha Baron Cohen was reportedly dining nearby. Witnesses said he looked up as the commotion unfolded, watched for a moment, then returned to his phone.

Chateau Marmont, a nearly century-old Hollywood institution on Sunset Boulevard, has long been a magnet for stars — and a place known for keeping their nights out under wraps. But it’s also been dogged by occasional complaints about wear and tear, with some reviews calling the iconic spot “perfectly imperfect.”

The hotel was contacted for comment about the incident, according to the report.