POTOSI, BOLIVIA—A mass grave containing the remains of hundreds of people was uncovered by construction workers in the El Minero district of Potosi in the Andes Mountains. Sergio Fidel of Tomas Frias University thinks that the site may have been an indigenous burial ground of slaves and indentured servants during the Spanish colonial era, when the ethnic Aymara were put to work in the silver mines, or victims of the collapse of a reservoir in Potosi during the 1600s. “We are talking about a common grave found at about 1.8 meters, and human remains are scattered over an area of four by four meters,” Fidel told AFP.