(CNN) -- At one time, teens Carlos Gonzalez, 16, and Juan Carlos Echeverri, 15, were classmates at Cathedral High School in El Paso, Texas. Like many who live along the border, both boys had strong ties to El Paso, and especially to neighboring Ciudad Juarez, Mexico. That's where they found themselves on Saturday, where they were gunned down at a car dealership by unknown assailants. Gonzalez and Echeverri were both U.S. citizens, the Cathedral principal told CNN. A third youth, 16-year-old Cesar Miramontes of Juarez was also killed in the incident. "Like many kids involved in this border reality of straddling two cultures, he had a lot of stress about what's going on in Juarez," the high school principal, Brother Nick Gonzalez, said of Gonzalez. The two are not related.
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Three teens killed Saturday at a car dealership in Ciudad Juarez
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Two of the victims were U.S. citizens, a school principal says
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Ciudad Juarez has been beset by severe violence in recent months
Just because the violence is on the Mexican side of the border, doesn't make it a @placeholder problem, he said.