Le Bilboquet denies entry out East during horrid storm that left trees falling at Calissa

No reservation? No safety!

A violent thunderstorm wreaked havoc in Sag Harbor on Saturday amid July 4 celebrations, tearing trees from the ground and whipping anything not bolted down into the air.

Within five minutes of the fireworks ending “all hell broke loose,” we’re told.

But a source told Page Six that buzzy French bistro Le Bilboquet denied people seeking refuge — because they didn’t have reservations.

“Emergency alerts went off on [the] phone informing us that there were 80 mph winds and to take shelter. People were huddling inside their boats, and running, and screaming outside,” they said.

“They wouldn’t let people in. They were like, ‘Do you have a reservation?’ They left people outside with 80 mph winds,” a source added.

Another source described the scene around the restaurant, saying “umbrellas and dishes falling over and injuring several people seconds after fireworks ended.”

“One woman got pushed to the ground. Another woman’s leg [was] cut,” they said.

Peter Cook, Morris Moinian, Howard Sobel, Maria Fishel and Sydney Sadick were all seen “running for shelter,” they added.

Bilboquet owner Philippe Delgrange told us they did the best they could. “Everyone from outside, from the very large deck, were safely moved indoors and we managed the crowd as best as [we] could to ensure the safety and comfort of our guests,” he said.

We hear that people who were turned away fled to American hotel.

Meanwhile, over at Calissa in Southampton, “The storm ripped apart 20 feet of fencing, one tree fell down and yet 100 people stayed to [see] Sam Ronson play,” says a source. “F-cking nuts,” they added.

Some New Yorkers cut their Hamptons visit short, and headed back to the city on Sunday, we hear.

“Half the town has no electricity and no internet! If you’re not connected to the internet, you’re f–ked,” one person said.

In Montauk, downed power lines on the tracks led to suspended service with the first train leaving at 3.15pm, leaving some having to pay for expensive Ubers back to the city.