A woman born and raised in Brooklyn went out dancing in Orlando with her son on Saturday night, and wound up among the 49 people killed in the deadliest mass shooting in American history. Brenda Lee Marquez McCool, 49 years old, is survived by her 21-year-old son and dancing partner, Isaiah Henderson, and 10 other children—six sons and four daughters.

McCool and her son were frequent patrons of Pulse, and though she usually came to New York City for the Puerto Rican Day parade, she decided to celebrate this year in Orlando, where she'd recently moved to be with her six youngest children, the youngest of whom is 12. Hours before the massacre, McCool uploaded a video to Facebook of couples at Pulse dancing jubilantly to salsa music.

When Omar Mateen began shooting at about 2 a.m., McCool told Henderson to get down and shielded him with her own body, a relative told the Daily News. Her son survived the massacre, but McCool was pronounced dead as of Sunday evening.

"That's how much she loved her kids," McCool's sister-in-law told the News. "If it weren't for her, he'd of been shot."

Noreen Vaquer, who'd known McCool since they attended kindergarten together in Brooklyn, told the Orlando Sentinel that her old friend "did the cowboy dancing. She did salsa. She did everything. She loved music." Vaquer also described her as a "fighter" who "doesn't take nothing from nobody."

McCool's fifth-oldest son, Farrell Marshall, has set up a GoFundMe page to raise money for his mother's funeral, as well as for his younger siblings, who were reliant on their mother's income.

"She just went out [Saturday] night and said goodbye to her children, and to be called 3 hours later that she has been hit by 2 gunshots and later pronounced dead...is beyond me," Marshall wrote. "One [d]ecision changed the lives of many. All I ask is for prayers and whatever you can to help me and [my] brothers [and] sisters to be able to pick up the pieces where she left off."

Born in Flatbush, where she attended kindergarten, McCool moved many times throughout her life: to New Jersey, California, and, ultimately, Orlando. She was a single mother and a two-time cancer survivor, according to the GoFundMe page, to which nearly 500 people have donated over $17,000 in the past day.

McCool was not the only New Yorker killed in the massacre: Brooklynite Enrique L. Rios, Jr., 25, was visiting Orlando for the weekend and was also killed by Mateen. Shane Tomlinson, 33, was also among the 49 victims of the shooting, and was originally from Queens, though he had lived in Orlando for some time. An NYU student, 20-year-old Patience Carter, was shot in the leg during the attack, but is stable, ABC reports.

The shooter, 29-year-old Omar Mateen, was an American citizen from New York who'd been living in Port St. Lucie, Florida when he carried out the worst shooting in the country's history. He was killed at the scene of the crime by law enforcement agents. It's been reported that he was homophobic, abused his ex-wife, and, just before the massacre, pledged allegiance to ISIS and made a reference to the 2013 Boston Marathon bombing. New reports also indicate that Mateen had gone to Pulse many times before, and had a profile on the gay dating app Jack'd. Mateen was investigated by the FBI twice in the past three years, but both cases were closed, and he had a valid firearm license in the state of Florida.

The NYPD has increased security citywide since the Orlando massacre, with a particularly heightened presence around LGBTQ clubs, events, and vigils. At a vigil outside the Stonewall Inn last nightthe second in as many days—thousands collectively recited the names of the publicly identified victims of the shooting, and Governor Cuomo made an impassioned call for strict national gun control.

There will be another vigil tonight, at Grand Army Plaza at 7:30 p.m.