Angela Brock had a longstanding dispute with the Think Life day-care center over the supervision and handling of her 4-year-old son.

So when she showed up Wednesday afternoon and Cedric ran to her crying that a worker had twisted his ear, she confronted the 23-year-old volunteer at the center for families with members who have the AIDS virus.In a fight witnessed by at least 10 children, including her three youngest, Brock was stabbed to death.

Left behind was an abandoned playground strewn with bloody rags amid strollers, a blue rocking horse and tricycles with streamers on the handlebars - and questions about how a dispute between two mothers of four could have gone so far.

The volunteer, Odette Green, is charged with killing Brock, a 29-year-old college student who seemed to be winning her battle against HIV. Her family was stunned at having to explain to her children that they'd never see their mother again.

"Her little girl, Terri, was running around saying, `My momma's dead.' But I don't think they'll really understand what has happened until they see her in the coffin," said Martha Gainey, Brock's mother.

Green, the worker charged with second-degree murder, had a daughter at the center where she had worked for about two weeks, police said. Witnesses said Green had pulled Cedric's ear and pinched him, and that the argument escalated after Brock hit Green in the face.

"She didn't like anybody touching her kids," Gainey said. "She was a great mother."