Marrieon Currie, 11 weeks old in January, took his final breaths as he was being doused in hot water, thrown down stairs, and beaten with a mop handle.

Bryanna Redmond, a skinny 2-year-old known as "Princess," died last year from a punch that split her spine.

Before they were killed - each by a parent, police say - all three children had come under the scrutiny of the city's child-protection agency, the Department of Human Services, which has the power to remove children from abusive homes. In each case, relatives or neighbors say they saw signs of danger. DHS either never saw those signs or discounted them.

Three years after a string of blunders by DHS were widely blamed for failing to prevent the torture-murder of toddler Porchia Bennett, an Inquirer investigation has found that young children are still regularly abused to death after coming to the attention of DHS. Although 3-year-old Porchia's death prompted the department to solicit expert advice on how to improve its investigative procedures, agency officials have failed to act on most of those recommendations.

From 2003 through 2005, at least 20 children died of abuse or neglect after coming to the attention of DHS, including 10 just last year, according to department records. Those numbers were coaxed out of the agency after four weeks of repeated requests.

In recent interviews, DHS Commissioner Cheryl Ransom-Garner acknowledged that the agency had made mistakes, but she declined to discuss them, citing confidentiality rules.

"I think DHS is doing a great job," she said. "Our staff do a heroic job every day, working to save Philadelphia's children. One child death is too many. And from every death we do a review to determine what can we do differently."

Those reviews, however, are secret.

"In Philadelphia, you can bury your mistakes," said Richard Gelles, dean of the University of Pennsylvania's School of Social Work.

Ransom-Garner declined to discuss details, but said DHS reviews had found that no policies or procedures were violated in six of the eight cases The Inquirer examined. In two of the cases, DHS could not answer the question by the time this article went to print.

There always will be deaths that child-protection authorities could not have foreseen or prevented. And the agency is in much better shape than two decades ago, when a class-action lawsuit forced it to improve.

But experts who consulted for DHS in recent years told The Inquirer that the agency's system for evaluating risk is inadequate. They said the agency still had not addressed key failings uncovered after Porchia Bennett's death.