After a national search, Mayor Nutter made an excellent choice in tapping an experienced child advocate to lead the troubled city Department of Human Services.

Ann Marie Ambrose will fill one of the last major open slots in the Nutter administration, and one of the most vital positions. She faces a daunting task to turn around a dysfunctional agency. A panel of national experts concluded that the $600 million agency had failed in its most basic mission and that 25 children had died needlessly over three years because of "significant system failures."

The department hasn't had a permanent leader since late 2006, when Mayor Street cleaned house after The Inquirer reported shocking cases of child abuse and neglect.

Acting Commissioner Arthur C. Evans Jr. has led DHS while a replacement was being sought. He has performed commendably, trying to boost employee morale and implement sweeping reforms.

The agency now needs a strong full-time leader to carry out 30 recommendations made by the blue-ribbon panel last year.

Ambrose begins the $150,000-a-year job June 23. With ties to both Philadelphia and Harrisburg, she should be able to start quickly. She is well-known in child protection circles and has a stellar reputation.

She currently oversees four regional offices in the state that manage licensing and child-abuse investigations for several public and private agencies. The city's deputy DHS commissioner for juvenile justice services from 2001 to 2005, she earlier ran the Youth Study Center and helped ease overcrowding at that facility. She was also an attorney for the Defender Association for 13 years.

Taking over DHS may pose Ambrose's biggest professional challenge. She wants to make DHS a national model for excellence in child welfare. That's an ambitious goal worth striving to achieve to protect the lives of the city's most vulnerable children.