A gunman opened fire on tourists at the ancient archaeological site of Teotihuacán (a vast pre-Columbian pyramid complex some 40 kilometres north of Mexico City) on Monday, killing a Canadian woman and wounding thirteen others — including two children and a Dutch national — before dying in an exchange of gunfire with police. Mexican authorities described the 27-year-old attacker from the state of Guerrero as a lone wolf with psychological problems, noting he carried books about the 1999 Columbine school shooting and had made far-right posts on social media. The attack, which drew widespread attention through viral footage, intensifies scrutiny over Mexico's security ahead of the 2026 FIFA World Cup, which the country is co-hosting, prompting President Claudia Sheinbaum to announce tightened security checks at tourist and archaeological sites nationwide.