JOSEPHINE "JOEY" GAY should have celebrated her 12th birthday this week. She should have been surrounded by friends and family in a place festooned with purple, her favorite color.

Chase Kowalski should have been working toward a Boy Scout merit badge and training for a triathlon. Avielle Richman should have been where her parents said she was happiest, on a horse.

Josephine, 7; Chase, 7; and Avielle, 6, were murdered five years ago at Sandy Hook Elementary School along with classmates Charlotte Bacon, 6; Daniel Barden, 7; Olivia Engel, 6; Dylan Hockley, 6; Madeleine F. Hsu, 6; Catherine V. Hubbard, 6; Jesse Lewis, 6; Ana Grace Márquez-Greene, 6; James Mattioli, 6; Grace McDonnell, 7; Emilie Parker, 6; Jack Pinto, 6; Noah Pozner, 6; Caroline Previdi, 6; Jessica Rekos, 6; Benjamin Wheeler, 6; and Allison N. Wyatt, 6. Educators Rachel D'Avino, 29; Dawn Hochsprung, 47; Anne Marie Murphy, 52; Lauren Rousseau, 30; Mary Sherlach, 56; and Victoria Soto, 27, were killed trying to protect children from the crazed gunman who stormed the Newtown, Conn., school with a semiautomatic rifle after killing his mother.

Sandy Hook, at the time, was the country's second-deadliest mass shooting in modern history. It was seen as a defining event that would finally lead to some sensible gun control. But not even the horror of elementary school children being slaughtered was sufficient to get action from a Congress in the thrall of the National Rifle Association. A ban on assault weapons was defeated, and Republican lawmakers blocked even modest legislation to improve background checks.

Five years later — after a series of mass shootings (including two deadlier than Sandy Hook) — that failure continues, and the gun lobby has become more emboldened. Witness the House's passage of legislation allowing people, including those with dangerous backgrounds, to carry concealed guns across state lines.

Things are more encouraging on the state level, where gun control advocates have increasingly focused. States have enacted laws to strengthen gun safety, including new or expanded background checks, and candidates promising gun control have won elections. "The reality is that the work doesn't really start in Congress. That's where it ends," said Shannon Watts, who founded Moms Demand Action the day after Sandy Hook. "This is a marathon, not a sprint," she said.

The Newtown Bee newspaper this fall invited the families of those killed five years ago to share their remembrances. "December 14th is always a difficult day for us," wrote Josephine Gay's family. "Not a day goes by that we don't feel the pain of his loss," wrote the parents of Chase Kowalski. Particularly touching is how these grieving families have tried to turn their tragedy into positive action. The Gays raise money to help children with autism, like their daughter. A foundation named for Avielle Richman funds research into violent behavior. The Chase Michael- ­Anthony Kowalski Sandy Hook Memorial Foundation supports family- and children-focused programs. Daniel Barden's father co-founded Sandy Hook Promise and travels the country advocating gun safety laws, as well as mental-health programs.

That these grieving families found the will to go on and take positive action puts Congress and its inaction to shame.