A Canadian tourist was killed and 13 other people were injured — including several Americans after authorities say a gunman held a group hostage atop a pyramid at Mexico’s famous Teotihuacan ruins.

The NY Post reports, the gunman climbed halfway up the Pyramid of the Moon — a nearly 2,000-year-old structure that was once used for ritual human sacrifice — just after 11:30 a.m. and opened fire on his cowering victims before finally turning the gun on himself, Mexican authorities said.