David Rosenblum died May 2, after suffering a heart attack Wednesday. He helmed the LGBT facility's legal-services department since August 2011.
In a statement, Mazzoni Center executive director Nurit Shein called Rosenblum a "tremendous friend and colleague, and a passionate and tireless advocate for the LGBT community."
"David had dedicated his professional career to standing up for those who most needed a voice, and his work at Mazzoni made a difference in the lives of hundreds of people each year," Shein continued. "David was loved and admired by all of us, and by countless others who worked with him. His loss will be deeply felt."
Prior to joining the Mazzoni team, Rosenblum served as the Equal Employment Opportunity Officer in New Jersey's Department of Labor and Workforce Development. He also served as the state's deputy attorney general and as a trial attorney at the U.S. Equal Employment Opportunity Commission.
He was a founding board member of Center for Lesbian and Gay Civil Rights, the predecessor to Equality Pennsylvania and co-founder and co-chair of the Philadelphia Bar Association's Committee on the Legal Rights of Lesbians and Gay Men.
He leaves behind a husband, family and friends and colleagues. Details on a memorial are pending.