Additional human remains from a 1985 police bombing on the headquarters of a Black liberation group in Philadelphia have been found at the University of Pennsylvania.

The remains are believed to be those of 12-year-old Delisha Africa, one of five children and six adults killed when police bombed the MOVE organization’s headquarters, causing a fire that spread to dozens of row homes. The violent confrontation, a rare bombing of American citizens by U.S. civilian authorities, led to lawsuits but no criminal charges against police or city officials.

Police seeking to oust members from their headquarters used a helicopter to drop a bomb on the house on May 13, 1985. More than 60 homes in the neighborhood burned to the ground as emergency personnel were told to stand down.