This longitudinal study involving repeated telephone interviews of a national probability sample assessed parents' and other adults' own psychological vulnerability, as well as any observed reactions of coresident and other children, immediately after September 11th, 2001 (N = 752) and again 1 year later (N = 484). For a significant minority of adults, perceived threat (from the terrorist attacks) to personal safety and security was both elevated and sustained. Single mothers and others living with children, non-Black Hispanics, and those reporting depressed mood immediately after September 11th were significantly more vulnerable to feeling threatened than other adults. In models controlling for all sociodemographic and psychological variables assessed in the study, adults and parents who encountered children they perceived to be fearful and upset following the attacks were significantly more likely than those not encountering distressed children to experience disrupted feelings of safety and security both immediately and 1 year after September 11th. These results suggest a generalized symbolic role for children in understanding the long-term trajectories of adult adjustment in the aftermath of terrorism. (Contains 4 figures, 4 tables and 5 footnotes.)