When you're not the master of your terrain, any number of things can go wrong. Two kayakers in a race slammed into a bridge, breaking their kayak in two and leaving them in the rushing water. Rescuers who knew the perils of the bridge were standing by, and quickly jumped to the rescue.
Nothin's bigger than a whale, but on land, and are probably used to not being in danger. That's not the case when they're on land, however, as one whale in Germany learned the hard way. Luckily, some people saw the beached whale and were able to push it back in the water.