John Lebarre, 57, and his 26-year-old daughter, Denielle Lebarre, may have died because of accidental carbon monoxide poisoning, according to the San Joaquin County Coroner’s Office.
Both were down below the deck as the houseboat camped in the Ski Beach area in Middle River of the San Joaquin Delta, about 10 miles east of Discovery Bay, on July 5.
Another woman sleeping above the deck survived. She found the other two dead when she went down below to use a restroom around 4 a.m., authorities said.
The woman called 911, and members of the Coast Guard and fire personnel responded.
The coroner will do an autopsy at a still undetermined time, but clues aboard the boat in the initial investigation point to carbon monoxide, authorities said. Andrea Lopez, a spokesman for the San Joaquin County Sheriff’s Office, said its first response team wore carbon monoxide detectors.
“Their carbon monoxide detectors that they had on them alerted them that there was carbon monoxide in the air,” Lopez said.
Carbon monoxide is a common danger for boaters, because it can build up in areas of the boat depending on how fumes are vented. The Centers for Disease Control and Prevention said when the carbon monoxide builds up, it can be lethal in less than a minute.
The CDC said symptoms of carbon monoxide poisoning include: headaches, confusion, fatigue, seizures, dizziness or loss of consciousness and nausea.