A German tourist was killed when his kayak capsized on the Colorado River in Arizona's Grand Canyon National Park, authorities said on Thursday, the second German visitor to die in the park this week. _0"> Park officials said Hans Uhl, 43, was on the first day of a commercial rafting trip on Wednesday when he was unable to right himself after his kayak overturned on a section of the river called Badger Rapids. When a rescue boat reached Uhl, he was initially responsive, officials said. But he soon lost consciousness, and efforts to resuscitate him by members of his group and park service medical personnel were unsuccessful. The National Park Service and the Coconino County Medical Examiner are investigating the death. It was not immediately clear where in Germany Uhl came from. On Wednesday, park officials said a 64-year-old German tourist collapsed and died on Monday from unknown causes at the popular Desert View Campground in the Southern Rim part of the canyon