About 500 people are killed in hippopotamus attacks each year. On Saturday, Kristen Yaldor was almost one of them. The 37-year-old American woman was on a river safari tour with her husband, Ryan, when she was suddenly attacked by a hippo that was said to be protecting her calf. The couple was on a guided canoe safari on Zimbabwe’s Zambezi River. Led by tour operator Wild Horizons, the safari group had three guests and two guides. While canoeing down the river, one of the guides spotted the hippo on the river’s right bank. He reportedly instructed the group to paddle...