Divers searched the water below Niagara Falls on Monday, searching for an exchange student from Japan who fell over a railing and into the deadly waters a day before.

Niagara Parks Police said the incident happened at about 8:30 p.m. when two female international students were taking photos on the Canadian side of the falls.

Trouble arose when one of the women, a 19-year-old from Japan, climbed onto the concrete ledge next to Horseshoe Falls to pose for a picture.

Police said the woman was sitting with her legs straddling the barrier. When she attempted to stand up again, she lost her footing and fell into the water below.

Kari Wilson, a visitor from Vancouver, told reporters, "I wish I could have done something." She wiped tears from her eyes as she spoke.

"She had one leg on either side straddling this post, and just very casual. She was just having a conversation with her friend," said Wilson, standing at the site near the falls where the woman fell.

The victim had been sitting casually on a stone part of the fencing and chatting with her friend, she said. "Her purse was sitting right behind her and I thought, 'Well, that's a stupid place to keep your purse,'" Wilson said.

Minutes later, the woman plunged into the Niagara River, about 24 metres upstream from the top of the falls.

The current quickly swept her over the 54-metre-high falls.

Emergency crews, including a provincial police helicopter, spent most of Monday searching for the woman with no success. Police told CTV Toronto that it could be weeks before a body is found.

The Japanese consulate in Toronto has been asked to contact the victim's family in Japan.

Niagara Parks Police Chief Douglas Kane said the woman's fall is a sober reminder that risking one's life for a photograph isn't worth it.

"If you're a young adult and you choose to climb over a restraining barrier, unfortunately there's consequences…in this case they were tragic," he said.

In his 35 years on the job, however, Kane said this is the first time he recalls someone falling.

Police searching for the woman's body Monday found human remains in the swirling waters below the falls, but they turned out to be remains of an unidentified male.

CTV Toronto's Austin Delaney said that security images captured at the scene show that the woman was using an umbrella.

"A gust of wind may have played a role," he said.

The incident comes a day after a 27-year-old man survived a fall into the Niagara Gorge, just north of the Rainbow Bridge.

The man fell into the Gorge after trying to get a better view of Niagara Falls with his friends. He suffered a head injury and a serious leg fracture.