oh here's this info I found too (apparently, more like 1ton? according this )
"If you don’t associate “hippo” with “vicious, aggressive man-killer”, you are clearly not watching enough Animal Planet Hippos kill more humans than any other animal in Africa (second to disease-carrying mosquitoes). Hippos are extremely territorial, highly unpredictable, and notorious for tipping boats that make the mistake of infiltrating their patch of water. What makes them most deadly however, is their bite. A hippo’s mouth can open 180 degrees. When it opens this wide it means the hippo feels threatened. Which means, so should you. One chomp from one of these monstrous water Goliaths can have 1,821 lbs of bite force! Their canines and sharp incisors (which they sharpen as they grind) can reach 20 inches in length. Get in the way of the their water, or calf, and you are up against a whopping 8000 pounds of bull rage that can charge at 18 to 30 mph!"