A hydrothermal explosion in Yellowstone National Park in the United States spewed rocks and debris Tuesday morning, forcing tourists to seek shelter and authorities to close the recreation area, according to the United States Geological Survey (USGS). Tourists who were at the site captured the phenomenon with their cameras. In those images, which can be seen above, one of the witnesses can be heard saying that “everything is destroyed.”

They show a tall column of mud and debris that forced visitors on a dock to run and leave the area. Specifically, the explosion occurred near Sapphire Pool, a hot spring pool in Biscuit Basin located just over two miles from the famous Old Faithful geyser in Wyoming.

Yellowstone National Park authorities were forced to close Biscuit Basin parking lot and boardwalks temporarily to ensure greater safety for visitors, although no reopening date has been set. “Hydrothermal explosions are violent and dramatic events that result in the rapid expulsion of boiling water, steam, mud, and rock fragments,” USGS said, adding that several such incidents have occurred in the park in the past.

USGS said in a statement that Tuesday’s explosion does not indicate that a volcanic eruption is imminent“Monitoring data show no changes in the Yellowstone region. Today’s explosion does not reflect activity within the volcanic system, which remains at normal activity levels,” USGS said. The agency added that its geologists are nonetheless investigating the explosion.