This story was originally published by the WND News Center.

A thermal zone in Yellowstone National Park, which is known for its geysers, hot springs, surface instability and volatile features, has exploded on tourists, destroying one of the park's famed boardwalks and terrifying watchers.

A report from the Jackson Hole News and Guide, in the pricey tourist town only a few miles from the park, said tourists were "traipsing" along the Biscuit Basin boardwalk when a "pool of hot water bubbling up from below the surface of the earth began rising up into the air."

"Some people stopped and started taking videos on their phones as the black cloud rose. Then, rocks started falling from the sky," the report said.

The Cowboy State Daily noted there were no injuries reported right away.

The eruption threw "an immense amount of black water onto a nearby boardwalk, destroying it, and sending tourists running for their safety.

The park's Biscuit Basin was closed down because of the event.

"The March family vising from California was touring the Biscuit Basin when Black Diamond Pool erupted. Steve and his wife, Vlada, were on the boardwalk with their two sons, Vlada's mother, and Issac Fischer, their guide from Casanova Guided Tours. They had a video camera running at the time, capturing the spectacular eruption even as they retreated to a safe distance. Other visitors also are seen fleeing the violent thermal spew," the report said.

Steve March said there had been a "large amount" of steam emanating from the Sapphire Pool before the explosion.

"We were walking toward Jewel Geyser when our guide pointed out the steam that suddenly shot out of Sapphire Pool. I guess that's never been witnessed before. And literally, a moment later, there was this massive explosion and a massive amount of rock (from Black Diamond Pool)," he told Cowboy State Daily.

He continued, "Our guide told us to run. So, we grabbed our kids, and we made our way to solid ground as soon as we could."

The report said the National Park Service noted Black Diamond Poll has been erupting – occasionally – since an earthquake in the region in 2006.

It had erupted just two months earlier.