The Early Show national correspondent Hattie Kauffman reports that a little-known danger to boaters, carbon monoxide poisoning, has taken the lives of many unsuspecting victims.
In northern Idaho over the Memorial Day weekend, Natalie Meredith, her husband, Jeff, son Jonathan, and a friend of his, packed up their boat and headed out. The joyride was to turn tragic.
Cpl. Randy Herman of the Clearwater County, Idaho Sheriff's Department told Kauffman he was one of the first to discover the Merediths' boat. It had run aground and was partially submerged. Inside, all four passengers were dead.
Jeff, who was at the helm, was "slumped over next to the steering wheel in the driver's seat," Herman said. "And the other occupants were in sleeping bags. (They) had been sleeping in the back."
Herman immediately suspected carbon monoxide poisoning. The four were probably dead before the boat hit the shore, Kauffman observed.
Natalie's mother, Marcy Smith, recalled, "They told me it was Natalie and Jeff. … I just dropped to my knees and said, 'I've got to get Jonathan.' And they said Jonathon was gone, too. And I'd lost all three of them."
Smith says her son-in-law was an experienced boater, adding, "I am sure that they had no idea that this could be a risk at all."
Carbon monoxide is colorless and odorless, Kauffman points out. It's released by boat generators, propane heaters and, in dangerously high concentrations, by boat engines.
Symptoms of carbon monoxide poisoning include headache, nausea, and dizziness.
Boating safety courses aren't required in most states, so authorities say most boaters don't fully understand the danger posed by carbon monoxide poisoning.
Jane McCammon, a former director of the National Institute of Occupational Health and Safety, told Kauffman, "Typically you don't see the initial symptoms of headache or confusion because these concentrations are so high that the person is there, talking, and then unconscious."