(CNN) A group of 18 kayakers paddling on Lake Superior on Monday had stopped to take in the scenic view along the Pictured Rocks National Lakeshore when, suddenly, sections of the sandstone cliff wall collapsed into the water just yards in front of them.

Maxim Rigaux was in the kayak closest to the rockfall. "We noticed it first when some little rocks fell down just next to one of our guides who was just under the cliff," he said.

The guide paddled away, and even bigger rocks began raining down.

Rigaux started recording and captured video of the massive rockfall as entire swath of the cliff cascaded into the lake, raising a plume of water and dust.

"We had no idea if there would be even more rockfall," he said. "We were kind of in shock and awe at the same time."

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