Possum Kingdom Lake, TX – The death of Lindsey Culver, 27, of Lubbock, who died Saturday, July 6, inside Hell’s Gate at Possum Kingdom Lake, has brought into sharp focus the effects of carbon monoxide poisoning. Precinct 3 Justice of the Peace Shawn Humphries said the autopsy report confirmed her death was by drowning, however, he said there was a 44 percent concentration of carbon monoxide in her system. While it was not listed as the cause of her death, it was a contributing factor, he added. “That is enough to put her to sleep,” said Debra Smith, a licensed paramedic, instructor and emergency room nurse. “She would have gone to sleep and slipped under water.” Brazos River Authority Chief Lake Ranger Robert Box said there has been more focus on CO in accident investigations over the last few years. “The one that scares me is operators who pull tubers up against the back of the boat when they go through a no wake area,” he said. “They’re breathing carbon monoxide, even from an outboard.” There is also the hidden hazard of CO for a person who is well behind the boat. “The hazard of going through a no wake zone is the propeller pushes it (CO) back to the person towed, where it will surface.” In areas such as Hell’s Gate, where there are large concentrations of boats and people, the dangers of carbon monoxide poisoning are greatly enhanced. “We’re always worried about Hell’s Gate,” he said. Those tying up or anchored in Hell’s Gate run generators or motors to keep batteries charged. As a result, there is the potential for higher concentrations of carbon monoxide. “They need to be conscious of where their exhaust ports are,” Box continued. He explained that swimmers should not get between boats that are tied together. In fact, those who want to get in the water should be extra cautious since CO is heavier than air and studies have shown concentrations are highest up to 2-feet above the water. “The worst place is under the swim deck,” Box added. “A house boat tied to a pontoon boat, kids will get under the pontoon boat to get out of the sun. Carbon monoxide is trapped under there.”