Tourists photographed at Niagara Falls capture the heartbreaking final moments before the horrific incident

An unremarkable photograph of two tourists standing together at Niagara Falls became famous because it showed a woman's last moments before tragedy occurred.

Niagara Falls is one of North America's many outstanding natural wonders. It lies on the border between the US state of New York and Canada and attracts approximately 12 million visitors each year.

With the incredibly high volume of visitors, tourists sometimes have to go to extreme lengths to get the perfect photo, which can have devastating consequences.

The beauty spot attracts millions of visitors every year (Mert Alper Dervis/Anadolu Agency via Getty Images)

It is estimated that since 1850, around 5,000 people have thrown themselves into the famous landmark – either intentionally or accidentally – with only 16 people said to have survived the fall.

On August 14, 2011, Canadian couple Andrea Smith and Jason Watson visited the falls and posed for a photo together in front of the popular Horseshoe Falls section of the national park, which is just across the Canadian side of the border.

The couple had their photo taken together at the lookout point and although the picture looks like any other tourist photo from the region, it was actually taken seconds before the disaster.

At the top left of the photo, a woman dressed in red can be seen seemingly crossing the railing that separates visitors from the precipice. This woman is 20-year-old Ayano Tokumasu, and her story serves as a tragic warning to anyone who ignores safety regulations in the pursuit of the perfect photo.

Tokumasu, who was originally from Japan, was an exchange student at the Hansa Language Centre in Toronto, Ontario, and had decided to visit the landmark on that fateful day.

The last photo of Ayano Tokumasu (Reddit)

While visiting the site with a friend, Tokumasu jumped over the railing so her friend could take a photo of her without other people being visible in the background. However, as she tried to climb back to safety, the student lost her balance, fell backwards into the water and was washed away.

Eyewitnesses stated that day that Tokumasu appeared to be sitting astride the railing to get a better view of the scenery. It took another four days before Tokumasu's body was found and recovered from the deep water.

Smith later spoke about inadvertently capturing her final moments on camera, telling Canadian newspaper Windsor Star (via Huffpost): “It actually sent shivers down my spine. [looking at the photo].

“We could have done something to save them and we didn't.”