It was a bit windy last week in New Zealand and the owner of a sawmill received a message asking if he had lost anything.  He answered, no he didn't think so. Reply - A water tank, maybe?  He went and checked and sure enough, his new 30,000 litre water tank was not where he left it.
The wind had blown it on its side and started it rolling.  It travelled 6 km down a road and at speeds of up to 50 km/hr!