Obviously, this is the one terror attack the government won't remind you about — and, in fact, would prefer you forget completely.

On May 13, 1985, a massive operation by the Philadelphia Police culminated in an all-out attack and bombing on the peaceful, radical movement dedicated to black liberation, MOVE. At the end of the day, 11 people — including five children — had been killed, 65 homes destroyed, and the relationship between law enforcement and civilians arguably changed forever.

Lest we forget.

MOVE advocated, according to Robin Wagner-Pacifici who has written books on the group, a "quasi-Rastafarian, anti-technology, and pro-animal-rights" lifestyle which Philadelphia police and some of the group's neighbors found antithetical to the typical American way of life. In 1985, the group resided at 6221 Osage Avenue, in what was considered a nice, family-oriented part of the city.

But city officials and police viewed MOVE's radical inclinations as a threat — and in the months preceding the attack, tensions had heightened considerably. To area residents, the standoff on May 13 didn't come as a surprise. But what happened next shocked the entire country.