Perhaps it is not actual crime statistics that they are afraid of. GT’s campus sits on the border of what appears to be one of Atlanta’s racial segregation dividing lines, with predominantly white areas on one side, and predominantly black areas on the other side. If your parents hold prejudicial attitudes against either black or white people, that may be the reason they think that GT is “dangerous”.
http://www.city-data.com/neighborhood/Georgia-Tech-Atlanta-GA.html
http://map.gatech.edu/