It was the knot in the tree that did it. He had to step around it and overextended himself. When he placed his foot, it slid on some moss and he fell off the log. He anticipated the splash and feel of the cold water, but somehow it never came. Instead, he felt his air cut off and he could not breathe. He panicked, struggling to look around to figure out what was going on. Little black specs were forming in his eyes. He was dangling around five feet above the rushing water, held up by his backpack which had snagged on the knot. The chest strap had slid up and was choking him. He struggled to unclasp it as he heard the backpack ripping. He finally managed to work the clasp free and he slid out of the shoulder harnesses and plunged into the water.