The city of Philadelphia is apologizing to Black individuals who were subjected to unethical medical experiments when they were incarcerated at the Holmesburg Prison from the 1950s through the 1970s. According to CBS News, the city issued a formal apology, granting the request of many community members who have been pressuring officials to speak on the issue.

“Without excuse, we formally and officially extend a sincere apology to those who were subjected to this inhumane and horrific abuse. We are also sorry it took far too long to hear these words,” Philadelphia Mayor Jim Kenney wrote in a statement.

At least 300 incarcerated people, many of whom were Black, developed lifelong health issues after the city allowed University of Pennsylvania researcher Dr. Albert Kligman to conduct dermatological, biochemical and pharmaceutical experiments. The group was exposed to viruses, fungus, asbestos and harmful chemical agents as part of the experiment.

Kligman conducted his research on mostly Black men who were awaiting trial and trying to save money for bail. The city said some of those who were subjected to the experiments were also illiterate.

Some of those exposed to the experiments formed a group to file a lawsuit against the university and Kligman in 2000. The complaint, however, was thrown out because of a statute of limitations.

The University of Pennsylvania issued a formal apology in 2021 and erased Kligman’s name from some of the honors he had received. Kligman died in 2010.