Tuesday marks 40 years since the 1985 MOVE bombing in Philadelphia, one of the darkest moments in the city's history.

Forty years ago, after a 12-hour standoff between police and members of the Black-led, back-to-nature group MOVE, the city of Philadelphia bombed a home, letting the fire spread across two city blocks through dozens of rowhouses. Eleven members of the group were killed. Five were children.