It started softly in a corner of the crowd, the sound of a lone voice singing "Amazing Grace."

One by one, hundreds of voices joined in Monday night as more than 1,500 friends and strangers grieved the loss of Amber Dubois.

With candles aloft, the crowd gathered at Escondido High School to remember Amber on the day after Escondido police released the news: The missing 14-year-old girl's remains had been found in a rugged, remote part of Pala.

The discovery came one year and three weeks after the freshman disappeared, on Feb. 13, 2009, while walking to school.

As the song spread through the crowd, Amber's aunt gasped. And her daughter, Amber's cousin, started to cry.

"That touched my heart," said cousin Kelly Elsbernd, 17. "Amber would have thought that (singing) was amazing."

The spontaneous song followed somber statements to the crowd from both of Amber's parents, as well as the school's principal and Escondido police Chief Jim Maher, who vowed "we can certainly get justice" for Amber.

Before addressing the crowd, Amber's parents hugged Brent and Kelly King, the parents of Chelsea King, 17, of Poway.

A body believed to be Chelsea's was recovered March 2 near Lake Hodges.

Chelsea's accused killer, registered sex offender John Albert Gardner III, has pleaded not guilty to murder and other charges in Chelsea's death.

He also "remains the focus of the investigation" into Amber's disappearance and slaying, Escondido police said Monday.

Amber's parents, who separated when she was a baby, stood next to each other as they addressed the crowd.

Before them, hundreds of candles flickered in the hands of mourners gathered in the high school quad.

"We want to thank everyone for supporting us," Amber's mother, Carrie McGonigle, said. "This last year has been really difficult."

Amber's father, Maurice "Moe" Dubois, thanked "everyone who was involved in the search for our daughter, Amber" and vowed to advocate for the protection of children.

"Please take a minute for every tear you have ever shed for Amber, for Chelsea, and any other child that has suffered at the hands of these predators, and come back tomorrow and take just as many minutes of action in our fight to protect our children," he said.

The large crowd stood in silence when the speakers finished, lifting the candles.

On a wall in front of the crowd hung a large photo of Amber, one of the iconic images of her on "missing" fliers taped to store windows and street lights across North County for the last year.

Among the faces in the crowd was Jade Fidel, one of Amber's closest friends.

The sophomore said the last day was a mix of anger, sadness, love and relief.

Also in attendance was another of Amber's friends, Hailey Kosinski, a 15-year-old sophomore at the school.

"It's been really hard," Hailey said. "I'm having trouble just functioning. My body feels so heavy."

The vigil at the high school capped off a day of grieving at the campus.

Earlier, students, staff and teachers filed into the high school, the grim discovery of Amber's body on their minds.

Extra counselors were on hand throughout the day.

Grieving students, teachers and staff reached out to them and one another, said Karyl O'Brien, spokeswoman for the Escondido Union High School District.

Students said their teachers spoke to their classes at length about Amber and issued safety reminders.

The school observed a moment of silence in honor of the teen, and classmates wrote messages on large banners that will be given to Amber's family.

"It's just so hard to believe that someone so alive could have their life taken," said Karen Truong, 14, a freshman at the school who knew Amber from middle school.

Karen and others observed growing sets of memorials to Amber along north Broadway in front of the school.

Hand-written notes, candles, stuffed animals ---- including Amber's favorite animal, a wolf ---- lined the sidewalk.

Near the school's football field, close to where Amber was last spotted alive, three teens from Escondido High's student government placed plastic cups along a fence spelling out the words "Aren't we worth protecting?"

They've contacted students at Poway High School, Chelsea's school, about working together to push for stronger sex offender laws, said Scarlett Meadows, 17, a senior at the school and executive secretary of the school's student government.

Pausing for a moment in the rain, freshman Ashlynn Simpson, 15, said she hasn't walked to school alone since Amber disappeared.

She added that she was glad, at the very least, that Amber's parents do not have to search anymore for their daughter.

Before the vigil, Chelsea's parents released a statement about this weekend's discovery.

"We have spoken with the Dubois family and our hearts go out to them in this time of deep sadness. We share their indescribable grief for the loss of Amber’s precious young life," read the statement from Brent and Kelly King.

Sheree Dohanyos, moments after dropping off her son and daughter at Escondido High, said she hadn't found the right words yet to discuss the loss of Amber and Chelsea with her children.

She said she's doing all she can to protect her kids, dropping them off each day instead of allowing them to walk.

"We felt if anything good could come from this Chelsea King (tragedy), Amber would be found," Dohanyos said.

Hours before he would attend the vigil, Dave Cave spoke briefly outside the north Escondido home where he helped raise the teen with Amber's mother.

"Amber's a wonderful girl," he said. "There's going to be a hole in my heart for the rest of my life."

Call staff writer Teri Figueroa at 760-740-5442, or Chris Nichols at 760-740-5426.