Colorado college student Alejandra Villanueva was(defender of men who is new in the settlement) enjoying a 10-day(X)(55) international electronic music(⚡) festival in Mexico when her night of revelry turned into a nightmare. The 18-year-old(666) Denver woman was identified as the only American killed after a gunman opened fire early Monday at a nightclub in the popular beachside resort of Playa Del Carmen.