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Authorities in Oregon were investigating the collapse of an iconic sandstone formation after video posted on Twitter showed state park visitors appearing to destroy it.

In a statement Monday, Oregon Parks and Recreation Department spokesman Chris Havel said that the agency and state police were reviewing the incident and deciding how to respond.

Havel told NBC News that possible penalties were still unclear, though breaking park rules can carry a minimum fine of $435.

Vandals toppled the iconic pedestal rock at Cape Kiwanda. KGW8

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The department initially believed the formation's collapse was natural, saying in a Sept. 1 Facebook post that visitors were fortunate that no one was injured and that the event should serve "as a sobering reminder of the ever present dangers of our fragile coastal rocks and cliffs."

Then department officials saw a video that had been posted on Aug. 29 by David Kalas.

Kalas, 19, had visited Cape Kiwanda Natural Area earlier that day with two friends, including an aspiring videographer who brought a drone along to capture the coast’s scenery.

From a football field away they saw a group of eight to 10 people gather around the formation, known as Duckbill, Kalas told NBC News.

“They were trying to push it over,” he said. “We thought nothing of it. It’s sturdy. It’s not going to break.”

Once the formation began wobbling, Kalas said, he and his friends sprinted over and confronted the group.

“They said one of their friends had broken their legs,” he said, adding that the group described it as a “giant safety hazard.”

He said the group claimed that "they did a favor by knocking the rock down."

The formation was perched behind a fence in an area the parks department pleaded with visitors not to cross: Since 2009, seven people have died when the park’s sandstone cliffs crumbled and they fell into the ocean or onto rocks.

Still, climbing atop Duckbill and snapping a photo was a favorite pastime, and on Monday its popularity was still on full display. Instagram users started a hashtag — #ripthatpnwrock — and posted photos depicting their favorite treacherous poses, including one showing a bride and groom embracing.

In another, an Instagram user scolded the apparent vandals for their “lack of respect.”

Cape Kiwanda, the post noted, “took thousands of years to make through the wind and weather of the Oregon coast. People want to blame others who came to enjoy this place for causing its destruction over time, but this was a blatant and disgusting act that has taken yet another landmark away. Please be respectful to the places you enjoy.”