A bison in Yellowstone National Park appeared to stumble into the scalding water of Grand Prismatic Spring, causing its death as tourists looked on during the park’s busiest season.

Tourists on the trip of a lifetime to Yellowstone National Park were left horrified after a bison stumbled into one of the park’s scorching hot springs. The animal—one of between 3,500 and 6,000 that inhabit the volcanic area of natural beauty—was seen thrashing around at the edge of the Grand Prismatic Spring before succumbing to the heat.