A group of kayakers on a tour at Pictured Rocks National Lakeshore got a real wake-up call Monday when a massive section of cliff fell into Lake Superior about 50 feet away from them.

None of the 18 kayakers were hurt. It was certainly a very close call and a reminder the beautiful sandstone cliffs are less stable than you may think.

The kayakers were out between Miners Beach and Mosquito Beach where cliffs reach up to 200 feet high. One of their guides says the moment will change the way he kayaks.

Van Ouellette-Ballas of Northern Waters Adventures says some smaller rocks had fallen near the group just before the massive section fell.

"We thought we were at a safe distance," said Ouellette-Ballas. "We got far away."

He was paddling away, and then a giant section fell into Lake Superior.

"I never thought I'd see that, hear it, smell it," said Van Ouellette-Ballas, noting the smell of extremely old dirt. "All the things. I was just blown away."

and

, two professional nature photographers, captured the moment with a drone they operated from a pontoon boat.

"We really thought there were kayakers underneath because it blew out so far," said Smithers.

Smithers says after they heard screams and saw the cliff fall, he flew his drone closer to make sure everyone was okay.

Blacklock says he's been hit by smaller rocks while kayaking, but he's never been up close to anything like this.

"For this group to witness something this big, this geologic change in the face of the cliffs, and for us to be able to get a video of it at the same time from the drone, is just an incredible coincidence," said Blacklock.

Richard Ziegler, a geology professor at Northern Michigan University, explained what happened isn't often captured on video.

"The slope has been over-steepened by waves pounding away at the bottom of the slope," said Ziegler. "The slope becomes too steep. Gravity takes over, and rock starts to fall."

Ouellette-Ballas says the experience is a wake-up call for kayakers.

"A lot of people think these rocks are stable and they're really safe, but as we can see, that's not the case at all," he said. "I'm definitely not getting under these rocks again, that's for sure."