A 26-year-old tourist from the Netherlands died on Tuesday, and two other Dutch nationals were hospitalized for minor injuries, following a boat ride on the Brazilian side of the Iguazu Falls after the vessel flipped over amid unusually high water levels caused by heavy rains.

Mark Lensink, his girlfriend, and her family were enjoying a ride at the base of Iguazu Falls, right where the waterfalls crash down, when the incident occurred.

The cause of the boat’s capsizing has not been determined, and local authorities are investigating.

Six Dutch tourists and two Brazilian crew members were aboard the boat during the accident, according to Brazil’s Chico Mendes Institute for Biodiversity Conservation, which manages national parks.

In a statement, the institute said it “deeply regrets” the death of the Dutch tourist, which occurred during the Macuco Safari tour Tuesday noon at Iguazu National Park in Paraná state.