Every Thursday afternoon at 3:30 mothers and grandmothers gather to march in front of the presidential palace demanding answers...they have done so for 30 years now. They demand to know the whereabouts of sons and daughters and husbands and wives who were detained by the ruling military junta between 1976 and 1983, and then disappeared. More than 9,000 people disappeared during the dirty war, and some human rights groups say as many as 30,000 may have been tortured and killed.