Mystic — As it might do at any ribbon cutting, the Mystic Fire Department raised the United States, Connecticut and Town of Stonington flags over a new playground at Williams Beach Sunday morning.

But a fourth flag also fluttered over the playground during the ceremony: pink and blue peace signs on a purple background, surrounding the words "Live Grace-fully."

The "grace" is for Grace McDonnell, one of the first-graders who was killed in the December 2012 shootings at Sandy Hook Elementary School in Newtown. The pink, purple and blue playground is a tribute to her memory, the latest in a series of playgrounds designed to commemorate Newtown victims as part of the "Sandy Ground Project: Where Angels Play."

McDonnell's parents, Lynn and Chris, chose Williams Beach-located just behind the Mystic YMCA-as the site of the playground because they were engaged in Mystic and their daughter loved the beach.

Peace signs, another of Grace's favorite things, were strung from trees and fences, carved into the cement and emblazoned on the sign leading into the playground. Vinyl panels displayed some of Grace's artwork. And during Sunday's ribbon-cutting, a plane circled overhead, trailing a banner that proclaimed, "To Mystic with peace, (love) and especially grace."

"Grace was an artist. Her paintbrush was her baton and her joyful life her canvas," said a teary-eyed Lynn McDonnell on Sunday. She thanked everyone involved in the "Sandy Ground" project, telling them, "your gifts of love, friendship and strength have lifted our family."

By 11 a.m. Sunday, the shiny new playground had a number of pink and purple balloons tied to it and looked ready to use. But getting it done on time wasn't easy, said Bill Lavin, a New Jersey firefighter who founded the "Sandy Ground" project.

"Every single place that we go has its own miracles," said Lavin, as he explained that the playground equipment arrived in Mystic at 10 p.m. Thursday-15 hours later than expected.

The truck carrying the equipment was escorted by state troopers through three or four states, he said, so it could reach the YMCA as soon as possible. When it arrived, the crew decided to work through the night to finish the playground.

About 150 volunteers worked until dawn, said Lavin, who added that "it actually brought tears to my eyes to see the commitment."

In addition to enthusiastic volunteers, every construction project needs a leader, said Lavin. In this case, the foreman was Jack McDonnell - Grace's older brother, who broke the ground and put in the last screw.

Jack attended Sunday's ribbon cutting with his parents. Throughout the ceremony, they were presented with several objects-a bell inscribed with "every time a bell rings, an angel gets its wings," a bagel designed in Grace's memory by the owner of Mystic's Wide World of Bagels and a bike for Chris McDonnell's next triathlon.

As the family turned to cut the ribbon, the sun suddenly broke through the overcast clouds and the crowd cheered.

Shortly after, energetic children raced past a purple panel displaying a peace sign and the words "Love Grace" and began to fill the playground.

k.catalfamo@theday.com