It's always a good idea to use your parking brake in the mountains. Wanna know how I know? THIS.

A couple of quick disclaimers before you click that play arrow above. First, no one was in this truck and no one was reportedly injured. Second, there is some very NSFW language when the person capturing the video realizes what's going on.

Now that I've got that cleared up, this video was taken on CO 7 near Rocky Mountain National Park according to the description on YouTube. It says the video credit goes to William Quast. That's some quick thinking, William. Now, go wash your mouth out with soap. Just kidding. Kinda.

This video is another reminder that things in the mountains can fall down places when their brakes aren't used. Your brake is your friend.