Where do broken hearts go on Valentine’s Day? Or any day for that matter? While romantics across the city were presumably holding hands over small bistro tables at overpriced restaurants or seated inside theaters in their best outfits, more than 150 people took refuge at an AllInOne Collective warehouse near Green-Wood Cemetery, in Brooklyn, communing over their shared grief instead of spending the night alone at home.

Jack Carrick woke up early Valentine’s Day morning for a cross-country flight from Seattle to New York, his soon-to-be new home.

He landed at about 9 a.m. on Tuesday and settled into his sublet in Brooklyn. After dinner that evening, Mr. Carrick, 29, headed to his first outing as one of the city’s newest residents: an art installation entirely inspired by broken hearts.

Posts about the event on Instagram caught his attention because he was still dealing with the end of a three-and-a-half-year relationship.

“It ended in August, but I’m definitely still processing,” a jet-lagged Mr. Carrick said. “It felt like it would be interesting to be around artists and other people and art that represents how I’m feeling.”

Mr. Carrick was not the only one.

“My ex and I broke things off the day after Valentine’s Day like a year ago,” said Mars Grace, 22, whose friend encouraged her to go to the event to take her mind off the holiday this year. (Ms. Grace had recently posted herself crying in an Instagram story.) “She was like: ‘You should just come out. Everyone’s going to be heartbroken and it’s going to be cathartic.’”

The one-night-only event, “Why Is Everyone Breaking Up Right Now?,” was the brainchild of the artist Blair Simmons, who just a few weeks earlier had herself been broken up with by her partner of seven years. After her group of friends swarmed in to support her, she realized that she wasn’t the only person in her social circle reeling from a recent breakup.

“It really feels so good to be around people who are going through it, and I feel really lucky that I have my squad,” she said in a phone interview before the show. “And my instincts are to bring more people together so that people don’t feel alone.”

After prematurely joining the dating app Hinge and immediately regretting it, Ms. Simmons, 29, decided to repurpose her profile as an open call for art and objects from users who had experienced breakups, including platonic ones, in the last 18 months. In just a couple of days, she received hundreds of messages and submissions on the app and elsewhere online.

Ms. Simmons and her fellow curators Maya Pollack, Molly Ritmiller and Silvia Beatriz Abisaab selected 29 artists to feature in the show. One of the pieces, a red checkered quilt peppered with short thoughts titled “Where I lay,” was created by the artist Natalya Kornblum-Laudi in part from a letter that she had written in response to a breakup. The color of the text matched the color of the fabric, making it hard to read except from inches away.

“The letter is so vulnerable, so I used every tool in my toolbox to mask the vulnerability,” Ms. Kornblum-Laudi, 26, said. “It’s about multiple people, multiple exes, multiple experiences. My dad’s in there.”

Sean Turner, a 19-year-old artist, submitted a series of self-portraits he had taken on film, titled “Our hearts may weep but our bodies sing,” which was made after a “friendship breakup” he experienced a year ago.

“I think it’s honestly worse than anything I’ve ever been through,” Mr. Turner said, adding that Tuesday’s show had been his first time being featured in an exhibition. “We had an argument and we couldn’t resolve it.”

Ms. Simmons decided to take a more literal approach with her own installation, “Please Take My Baggage,” a roughly seven-foot-tall iridescent tower of hundreds of small bags and boxes filled with things from the apartment she had previously shared with her ex. Some of the objects were former gifts — which obviously had to go — but others were more benign fragments, things that simply reminded her of their relationship. Instead of throwing these miniature time capsules out, she invited guests to take a bag home at the end of the night.

“Everybody will get a little piece of my broken relationship to go,” she explained.

Tickets for the group show were $15. (Ms. Simmons said the proceeds had gone directly to the participating artists and curators.) When they weren’t admiring the installations or laughing over wine, pink marshmallow cereal treats and ceviche, guests were stealing early peeks inside Ms. Simmons’s “baggage,” trying to determine which they would go home with.

Among the gifts claimed on Tuesday were an Ostrichpillow, a glittery cowboy hat, tote bags, framed art prints, dinnerware, caffeine supplements, a can of pinto beans, a small bottle of adhesive remover, instant ramen and a tube of chips. Word traveled in the room that someone had picked a bag with glasses inside that appeared to be from Fendi.

One woman pulled out a white cereal bowl with a blue fish on it before tucking it back inside the bag. Later in the night, a man would find the same bowl and immediately tuck it under his arm with modest excitement.

Ms. Simmons said that she was not only feeling supported during this tough time, but that she was proud that she could support others on what can be a rough day for the singles.

“A lot of people have said that it’s nice to be able to be around each other in a moment that could be hard and instead we made it a little fun, a little dark, a little silly,” she said at the show. “This has been a pretty transformative night for me.”

About 20 minutes before things wrapped up, as the sounds of Lauryn Hill’s “Ex Factor” boomed from the speakers, the last handful of guests sifted through the remaining bits of the pile, while others departed with smiles into the quiet Brooklyn street.

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