YSK: Even slow-moving water presents incredible risk. Trying to move across a fast-moving stream or flood water is suicide. A 1-meter cube of water is the definition of a ton. Imagine the water as 1 ton cubes moving at that speed, and you will see how cars get swept away trying to cross.
from /r/YouShouldKnow
YSK：即使是缓慢流动的水也会带来难以置信的风险。试图穿越快速流动的溪流或洪水就是自杀。1米长的水立方是一吨的定义。想象一下，水是1吨的立方体，以这种速度移动，你就会知道汽车是如何被冲走的。