By Cherri Gregg

PHILADELPHIA (CBS) — An organization founded by a Philadelphia mother who turned a tragic loss into an agent of change will celebrate a milestone.

As a business owner and mother of four, Movita Johnson-Harrell would open the doors to her home to everyone on her North Philadelphia block.

“We had the huge back yard with the basketball court,” she said.

But gun violence forced her to move her family out of the city. Tragically, that didn’t stop death from knocking. Her son Charles was shot and killed in a case of mistaken identity while picking up his sister in January 2011.

untitled58 Grieving Mother Turns Tragedy Into Triumph

(credit: Cherri Gregg)

“When my son was taken, it was like a piece of my heart was ripped out,” Harrell said.

But the social worker picked herself up, and three months after her son’s death, Harrell founded The Charles Foundation.

“Charles is an acronym for Creating Healthy Alternatives, Results and Less Emotional Suffering,” she explained.

They launched “Be the Change” for youth likely to kill or be killed, going into schools, mentoring youth and providing support.

“It makes me feel my son didn’t die in vain,” Harrell said.

On Saturday, they’ll celebrate the change with a gala. Visit the foundation’s website for details.