(REUTERS) - A 23-year-old man who was scalded to death after falling into a boiling Yellowstone National Park hot spring in June was trying to test the temperature of the bubbling pool for a soak when he slipped in, according to a report on the incident.
Colin Nathaniel Scott was seen by his sister, Sable, plunging into the hot spring near Pork Chop Geyser on June 7.
His body was never recovered and according to the US Department of the Interior report, likely dissolved in the highly acidic, 212 degrees Fahrenheit water.
The department's 60-page report, first made public this week following a Freedom of Information Act request by local Montana television station KULR, says that the brother and sister had left the park boardwalk and entered a dangerous area marked by warning signs.
"There's a closure in place to keep people from doing that for their own safety and also to protect the resources because they are very fragile," Lorant Veress, a deputy park ranger, told KULR.
"But, most importantly for the safety of people, because it's a very unforgiving environment."
Veress told KULR that Colin and Sable Scott were"specifically moving in that area for a place that they could potentially get into and soak. I think they call it Hot Potting."
The report describes the accident in grim detail, saying that Sable Scott had been videotaping the hike and recorded her brother's death. The videotape was not included in the report and sections describing its contents were redacted.
But rangers and other law enforcement personnel who responded to the scene after Sable Scott sought help described seeing her brother's head and upper torso briefly floating face up in the hot spring, a crucifix around his neck.
Only his wallet and orange-and-black flip flops, one of them badly melted, were later retrieved. A photo of the scene shows one of the shoes at the edge of the murky pool as steam rises from its surface.
Each year some four million people visit Yellowstone, the first national park established in the United States. It encompasses some 3,500 square miles across Wyoming, Idaho and Montana.
In 2014 a Dutch tourist was fined US$3,000 (S$4,300) after crashing a drone aircraft into Grand Prismatic Spring, a Yellowstone geothermal feature known for its brilliant colors caused by bacteria and minerals.