No cartels involved - but Mexico's pyramid attack prompts new concerns 7 hours ago Will Grant, Mexico correspondent, reporting from Mexico City and Vanessa Buschschlüter, Latin America digital editor Reuters/Luis Cortes The National Guard was among the security forces deployed to the site after the shooting The authorities in Mexico are still piecing together how a typical morning at the ancient pyramid complex of Teotihuacán, one of the country's foremost tourist destinations, descended into terrifying gun violence on Monday. The video footage is disturbing. A gunman stands atop the imposing Pyramid of the Moon and opens fire on the tourists around him, who cower for cover among the pre-Hispanic stone structures. After the ordeal, a 32-year-old Canadian woman had been killed and the gunman had died from a self-inflicted gun wound. Tourists from several nations, including Russia, Colombia and Brazil, were treated for their injuries in local hospitals.…