Six wild elephants drowned after a herd rushed to save a calf who slipped off a notorious waterfall.
Officials in Khao Yai Nationa Park, Thailand, were alerted to the sounds of elephant cries at 3am on Saturday and went to investigate.
This followed a number of incidents of park rangers spotting elephants blocking a road on Thursday and Friday.
When they arrived at the falls, they discovered the calf, aged about three, drowned in the first tier of water, before finding five adults dead at the bottom.
Two other elephants were also found struggling on a cliff edge nearby, and have been moved by Thai authorities.
Edwin Wiek, the founder of Wildlife Friends Foundation Thailand, said the surviving pair of elephants may have difficulty surviving as elephants rely on their large herds for protection and finding food.
He told the BBC : "It's like losing half your family. There's nothing you can do, it's nature unfortunately."
The incident could also take an emotional toll, as elephants have been known to display signs of grief
The fall has a history of similar incidents with a herd dying in exactly the same place in 1992.
Around 300 wild elephants currently live in the park, which covers more than 2,000 square km (772 square miles) of forest and grassland.
It is home to various wild animals, including bears, elephants and gibbons, and is a popular destination for tourists.
Park chief Tunya Netithammakul ordered the waterfall to be temporarily closed to visitors following the incident.
Elephants are Thailand's national animal but their numbers have dwindled to only a few thousand due to deforestation.
