expressing anger. international politics and domestic politics seemed to be decided by violence. and violence only begets violence. >> from the underground, that radical left wing group, the weathermen promises more attacks on the establishment around the entire country, starting next week. the medium for this message was a tape recording, reputedly by the weatherman rebel leader, bernadine donnor. >> sisters and brothers, we are not just attacking targets, we are bringing the giant to their knees. >> guard your children, guard your doors. >> at one minute before 1:00 this morning, the switchboard at the capitol received a phone call. a man's voice said a bomb would go off in the building in half an hour. at 1:30 in the morning, it did. credit for the bombing was claimed by the weather underground. >> in 1971, it appears that weather is really aiming even higher.