Former U.S. Rep. Carolyn McCarthy, who successfully ran for Congress in 1996 as a crusader for gun control after a mass shooting on a New York commuter train left her husband dead and her son severely wounded, has died. She was 81.

News of her death was shared Thursday by several elected officials on her native Long Island and by Jay Jacobs, chair of the New York State Democratic Committee. Details about her death were not immediately available.

McCarthy went from political novice to one of the nation’s leading advocates for gun control legislation in the aftermath of the 1993 Long Island Rail Road massacre. However, the suburban New York Democrat found limited success against the National Rifle Association and other Second Amendment advocates.

McCarthy announced in June 2013 that she was undergoing treatment for lung cancer. She announced her retirement in January 2014.

“Mom dedicated her life to transforming personal tragedy into a powerful mission of public service,” her son, Kevin McCarthy, who survived the shooting, told Newsday. “As a tireless advocate, devoted mother, proud grandmother and courageous leader, she changed countless lives for the better. Her legacy of compassion, strength and purpose will never be forgotten.”

New York Gov. Kathy Hochul directed flags on all state government buildings to be flown at half-staff in honor of the congresswoman on Friday.

“Representative Carolyn McCarthy was a strong advocate for gun control and an even more fierce leader,” Hochul said.

Democratic U.S. Rep. Tom Suozzi said the nation has “lost a fierce champion.”

“Carolyn channeled her grief and loss into advocacy for change, becoming one of the most dedicated gun violence prevention advocates,” Suozzi said on X.

She became a go-to guest on national TV news shows after each ensuing gun massacre, whether it was at Columbine High School or Sandy Hook Elementary School.

Known as the “gun lady” on Capitol Hill, McCarthy said she couldn’t stop crying after learning that her former colleague, Rep. Gabrielle Giffords, had been seriously wounded in a January 2011 shooting in Arizona.

“It’s like a cancer in our society,” she said of gun violence. “And if we keep doing nothing to stop it, it’s only going to spread.”

During one particularly rancorous debate over gun show loopholes in 1999, McCarthy was brought to tears at 1 a.m. on the House floor.

“I am Irish and I am not supposed to cry in front of anyone. But I made a promise a long time ago. I made a promise to my son and to my husband. If there was anything that I could do to prevent one family from going through what I have gone through then I have done my job,” she said.

“Let me go home. Let me go home,” she pleaded.

McCarthy was born in Brooklyn and grew up on Long Island. She became a nurse and later married Dennis McCarthy after meeting on a Long Island beach. They had one son, Kevin, during a tumultuous marriage in which they divorced but reconciled and remarried.

McCarthy was a Republican when, on Dec. 7, 1993, a gunman opened fire on a train car leaving New York City. By the time passengers tackled the shooter, six people were dead and 19 wounded.

She jumped into politics after her GOP congressman voted to repeal an assault weapons ban.

Her surprise victory inspired a made-for-television movie produced by Barbra Streisand. Since that first victory in 1996, McCarthy was never seriously challenged for reelection in a heavily Republican district just east of New York City.

Some critics described McCarthy as a one-issue lawmaker, a contention she bristled about, pointing to interests in improving health care and education. But she was realistic about her legacy on gun control, once telling an interviewer:

“I’ve come to peace with the fact that will be in my obituary.”