Wild lights and smoke effects accompanied the music. Tickets went for as much as $2,500 per person. Nearly 100 security guards and police officers were on duty. In many ways it resembled a typical concert by the Chainsmokers, the D.J. duo known for catchy pop-electronica anthems and collaborations with other top artists. And it might have been just another big summer event in the Hamptons, except that Saturday's show at Nova's Ark in Bridgehampton took place in a world where concerts and other major events have been silenced by the Covid-19 pandemic.
Now the Chainsmokers' event management companies are being investigated by Southampton Town, and Southampton Town is being investigated by the New York State Department of Health, officials announced this week.
"The concert that happened in the town of Southampton was just a gross violation of not only the public health rules — it was a gross violation of common sense," Gov. Andrew M. Cuomo said in a press conference this week.
Southampton Town Supervisor Jay Schneiderman, whose own band was one of the opening acts, has said the Chainsmokers' event companies will likely be cited for violating their event permit, which had been reviewed by the town clerk and other officials before being approved.
According to the event permit, there was space for about 600 cars, and it has been widely speculated that there were as many as 3,000 people in attendance.
By day on Saturday, photos emerged of people packing the beaches elsewhere on the South Fork, and by night, many more were rocking out on the expansive Bridgehampton property, home to the well-known Nova's Ark sculpture series by the late artist Mihai Popa, who was commonly known as Nova.
"The production team was amazing," Tundra Wolf, who owns the 95-acre property, said by phone on Monday. "They set up in record time and there was no damage to the property."
By her account, social distancing was observed and masks were worn, which was a condition of the event because Nova's Ark cares about the safety and well-being of all of its visitors, she said.
But by other accounts — and numerous social media videos — social distancing fell by the wayside as soon as what has been described as "a V.I.P. area" drew crowds to the front of the stage.
"As proposed to us, it met the guidelines. However, the organizers didn't strictly adhere to it," Southampton Town Supervisor Jay Schneiderman said late Monday. "It's unfortunate, because we're trying to raise money for charity and trying to find ways for people to come together safely."
When Mr. Schneiderman's band played, "there was no V.I.P. area. It was just cars," he said.
David Solomon, the C.E.O. of Goldman Sachs, a.k.a. D.J. D-Sol, played an opening set, according to Bloomberg News, and Jesse Warren, the mayor of Southampton Village, delivered opening remarks. On Tuesday, Governor Cuomo said the state is also looking into public health violations in Southampton Village.
Mr. Warren said the governor had seen news coverage about crowds at 75 Main, a restaurant and bar in the village. "We have given 75 Main numerous warnings. . . . We have asked for help from the State Liquor Authority and Department of Health to help us get the one or two business owners who are not in compliance into compliance. The large majority of our business owners are doing an excellent job."
Proceeds of the concert were to benefit the Southampton Fresh Air Home, No Kid Hungry, and the Children's Medical Fund of New York.
Southampton Town's attorney, James M. Burke, emphasized that point to Dr. Howard Zucker, New York State's Health Department commissioner, in a letter sent late Tuesday afternoon.
"Whether it's strictly enforcing state mandates including social distancing guidelines or working with nonprofits to address critical needs such as food insecurities, the Town of Southampton has stepped up and continues to set an example in safeguarding the health of the public here on the East End," Mr. Burke wrote.
The letter was sent in response to Dr. Zucker's call for an official account. "I am at a loss as to how the Town of Southampton could have issued a permit for such an event, how they believed it was legal and not an obvious public health threat," the commissioner wrote in a letter to town officials on Monday.
Data from the governor's office show that the daily Covid-19 infection rate on Long Island, meaning the percentage of new positive cases out of the total number of tests given, fluctuated from 1.3 percent on Saturday to 1.5 percent on Sunday to 1.1 percent on Monday, all low compared to the rates in other states. Southampton Town had 1,000 confirmed cases of the virus as of Tuesday, and East Hampton had 231, but countywide there have been more than 43,000 confirmed cases.
Mr. Burke wrote that the terms of the event permit stated guests were to be restricted to "an assigned personal area adjacent to their vehicle which they could not leave except to use the restroom." Free masks and sanitizer were given out. There were 64 private security guards employed by the event management, plus "police detail as well as the chief fire marshal and several support staff," he wrote.
"For most of the evening, the event appeared to be running smoothly. It wasn't until later in the evening that town officials observed possible permit violations occurring in an area immediately in front of the stage. There was no reference to such an area in the permit application and the town did not approve any such gathering space."
Aerial videos documented the event, Mr. Burke said, and he offered them up for viewing in his letter to Dr. Zucker.
The Chainsmokers' event companies, In the Know Experiences and Invisible Noise, could not be reached for comment Tuesday night. But in a statement on Monday, the companies defended their procedures. They "followed the guidelines created by the Centers for Disease Control and Prevention and made best efforts to ensure New York's social distancing guidelines were properly maintained throughout the event. We collaborated with all state and local health officials to keep everyone safe, create awareness for local businesses, provide work to over 350 people who have been unemployed as a result of the pandemic, and to bring some joy into people's lives during these difficult times," they said.
People were asked to disclose past positive Covid-19 diagnoses and any previous contact with anyone who tested positive for Covid-19, according to the statement. Guests were asked to self-monitor their temperatures for two weeks to be sure their body temperatures were below 99.5 degrees Fahrenheit. He said announcements and reminders were made every 30 minutes from the main stage to maintain order.
"Guests were also instructed that they would not be allowed to leave their designated spots for any reason other than to use the restroom facilities. . . . The event organizers followed all proper and current protocol, including spacing each spot more than six feet apart, positioning sanitizing stations throughout the open grounds, temperature checks for all attendees, sanitization of restrooms every 10 minutes, local security enforcing guests to wear their masks both in and out of their designated areas, contact tracing, clearly marked parking zones, as well as providing complimentary face masks upon arrival."