A 48-year-old visitor to Yellowstone National Park suffered severe burns late Sunday night after he left the boardwalks and fell into scalding thermal water near the Old Faithful Geyser.

The injured man was identified by Yellowstone officials as Cade E. Siemers, a U.S. citizen who’s been living in India.

With poor weather ruling out a direct helicopter flight from Old Faithful, Siemers was taken by ambulance to the airport in West Yellowstone, Montana, and then flown by airplane to a burn center in Idaho Falls. He suffered burns on “a significant portion of his body,” park officials said in a Monday news release.

Yellowstone rangers and paramedics responded to the Old Faithful Inn — where Siemers had been staying — around midnight Monday morning. Siemers told rangers that he had gone for a walk without a flashlight, leaving the boardwalks before tripping into a hot spring. He then “got himself back to his hotel room and called for assistance,” according to the release.

In speaking with Siemers, rangers reportedly detected signs that he had been drinking. When rangers later checked the area, they reportedly found Siemers’ shoe, his hat and a beer can near the geyser, along with footprints going to and from the off-limits area. They also saw blood on the boardwalk.

Yellowstone officials said their investigation was continuing on Monday — including checking to see whether Old Faithful’s cone was damaged in the incident. Once the investigation is finished, a report will be forwarded to the U.S. Attorney’s Office for possible charges, the release said.

Yellowstone officials added that, “The ground in hydrothermal areas is fragile and thin, and there is scalding water just below the surface. Visitors must always remain on boardwalks and exercise extreme caution around thermal features.”

According to park records, this marked the first serious injury in a Yellowstone thermal area in more than two years. The last incident occurred in June 2017, when a man was severely burned after falling in a hot spring in the Lower Geyser Basin. Another man died after leaving the boardwalk and falling into a hot spring at Norris Geyser Basin in June 2016.

While visitors have escaped injury over the past two years, Sunday night’s incident was only the latest case of park visitors getting too close to Old Faithful: Two men are currently facing criminal charges after they reportedly walked up to the geyser earlier this month, while another man was punished for doing the same thing in September 2018.