During the freedom summer campaign of 1964 in mississippi what happened?

During the Freedom Summer campaign of 1964 in Mississippi the three civil rights workers were found dead.

Freedom Summer constituted a 1964 voter registration project in Mississippi, part of a fight by civil rights groups including the Congress on Racial Equality (CORE) and the Student Non-Violent Coordinating Committee (SNCC) to expand black voting in the South. The goal was to increase black voter registration in Mississippi, so that, the Freedom Summer workers included black Mississippians and over 1,000 out-of-state, most of them white volunteers.

i think it was because of how protected egyptian civilization was was which allowed them to evolve without much outside influence.

ba geologist finds four sedimentary rock she determines that no geologic events have shifted the layers she labeles them a,b,c,dbfrom top to bottom