A man in his early 20s is presumed to have died after he fell off a boardwalk into a hot spring at Yellowstone National Park.
A statement from the park said the incident, which was first reported by a witness, is being treated as a probable fatality and rangers have not yet located the victim.
Thermal areas in the park can reach temperatures of 200 degrees fahrenheit.
The Norris Geyser Basin is closed to the public while the investigation is ongoing.
“The features in the basin change daily, with frequent disturbances from seismic activity and water fluctuations,” according to the park website.
The news comes the same week that a 13-year-old boy was burned by hot water in the park. He reportedly suffered burns around his ankle and foot as his father, who was carrying him, slipped into the park’s Upper Geyser Basin.
His father refused treatment although he was burned too, as reported by The Billings Gazette.
The start of the tourist season at the world-famous national park has been eventful.
A group of men reportedly posted pictures and videos on social media as they dipped a hand into water that can reach boiling point.
Tourists have been charged with loading a baby bison in the back of their car to take pictures with it - the animal was later euthanized as it was rejected by the herd.
This month, a woman was headbutted by an elk after trying to take a selfie with the animal in the background.
Despite several high-profile incidents, the park celebrates its 100-year anniversary in August 2016 after seeing record visitor numbers last year.
Visitors are told to stay on the boardwalks and to remain at least 25 meters away from animals like bison and elks.
