A day at one of Mexico’s most iconic landmarks turned deadly in a flash — gunfire erupted at the famed Teotihuacán pyramids and sent tourists into full-blown panic.

Authorities say a gunman opened fire Monday near the Pyramid of the Moon … killing a Canadian woman and injuring at least 13 others before turning the weapon on himself.

Officials identified the suspect as JulioCesarJassoRamirez, who they claim climbed up to the mezzanine level of the pyramid around 11 AM and began firing. A witness told Reuters they had just come down from the structure when they heard what sounded like “pops,” followed by a stampede of visitors scrambling to get out of harm’s way.

The chaos was immediate … tourists ran in every direction, some tripping or falling as they tried to escape. One witness said a young boy was shot in the leg, though it’s still unclear how many victims were directly hit by gunfire versus injured in the rush.

The gunman reportedly stayed elevated on the structure, shouting and holding what appeared to be a digital tablet while firing multiple rounds — many of them into the air rather than directly at people.

Among the injured were tourists from the U.S., Colombia, Brazil, and Russia, as well as another Canadian. Officials say several victims were hospitalized, including a 6-year-old child.

Mexican President Claudia Sheinbaum addressed the tragedy … saying the country is “deeply pained” by the violence and offering condolences to the victims and their families.