. >>> franz josef glacier? new zealand is considered a gem. group of tourists had a fantastic time and on their way down, from the glaser, they experienced something even more spectacular. ♪ >> a rock slide? >> this is a rock fall and a massive amount of rocks came crashing down. >> oh, boy. >> with the tourists not very far away. >> it looked like somebody set off dynamite. >> that's exactly what it looks like. everybody was completely stunned, but they did have expert guides that immediately guided the tourists to cover their heads. so that's what you're looking at here when you see the camera go off to the side. >> they had to take an emergency stance and cover their head and everything? >> yes. they were extremely close. they were completely covered by dirt and dust. and, some of the rocks got really close to them. you can see one of the tour guides pick up a rock and show it to them. >> got this on camera. >> that's not a small rock. >> no. this happened in october, but the video is tarting to really make its way around the web. the entir