ANCHORAGE, Alaska (KTUU) A large group of experienced rafters up river from Lion's Head were preparing to navigate the Matanuska River late in the afternoon Saturday. They held a safety briefing with the knowledge of the fatality in an area they would soon be traveling.

According to the Alaska state trooper dispatch, Martin Rinke, 63, of Sutton, "succumbed to injuries received and was pronounced deceased at the scene" after the raft he was in overturned in the river near the Lion's Head. Locals said that area of the river is known to have class III and IV rapids. "This section here, there's a lot of big boulders, a lot of holes. With Alaska white water in general the thing that makes it so dangerous is they're active rivers so they're still eroding the shorelines,” Ryan Roberts said.

Roberts has ran the river for the past eight years, ”there's still a lot of trees, debris being flushed into these systems and every time you go on one it's a totally different river. You're having fun in the sun and the next think you're flipped over," Roberts said.

While using pack rafts Roberts has been flipped into the river but he says he has never flipped a larger raft. He said once it happens there may be little you can do to help someone else in trouble. "Your safety is to get to the boat so getting on top is safe,” Roberts said. Roberts said most rafts will have a line on the side, “and everyone pulls the boat back over and flips it over — which is challenging to do in the middle of a white water section," he said.

According to the AST dispatch, Rinke was navigating the river with a group of four people, each using their own inflatable kayaks.