Two canoeists were mysteriously found dead after setting out shortly before midnight on California's Tomales Bay, prompting an investigation.
The Marin County Sheriff's Office said the canoeists were found unresponsive Sunday.
Authorities have publicly identified only one of the two victims as San Francisco resident Casey Flynn Melia, 36.
NURSE IMPALED BY POLE DURING HIKE FORCED TO TREK 10 MILES FOR HELP: 'A FREAK THING'
The two individuals had been camping along Tomales Bay before setting out in a canoe shortly before midnight Saturday, according to officials.
"When the pair did not return the following morning, members of their camping party alerted emergency services via 9-1-1," a statement said.
"First responders immediately initiated a search-and-rescue operation."
After finding Melia's companion "unresponsive in the water," rescuers later located Melia, who was "unresponsive near Hog Island."
US WARNS TRAVELERS TO AVOID PICTURESQUE COUNTRY AS SECURITY RAPIDLY WORSENS
Both were subsequently pronounced dead.
"A forensic post-mortem examination and routine toxicology testing are scheduled for later this week," the statement said.
"The official cause and manner of death remain pending, awaiting the final findings of a joint investigation conducted by the Marin County Sheriff's Office, the USCG [United States Coast Guard] and the NPS [National Park Service]."
Officials added, "Because this remains an active investigation, no further details are available from the Coroner Division at this time."
CLICK HERE TO SIGN UP FOR OUR LIFESTYLE NEWSLETTER
Fox News Digital reached out to the Marin County Sheriff's Office for additional information.
Nighttime kayaking has become increasingly popular in the Point Reyes area as visitors take to the water after dark to see bioluminescence, according to the NPS.
The bay contains bioluminescent plankton that creates a blue-green glow in the water when disturbed.
But officials warn that kayaking after dark requires extra caution and additional safety measures.
CLICK HERE FOR MORE LIFESTYLE NEWS
"While kayaking at night, it is essential that you remain visible to other boat traffic," NPS' website states.
"We strongly recommend the use of a working 360-degree light for all vessels, including kayaks and canoes."
TEST YOURSELF WITH OUR LATEST LIFESTYLE QUIZ
The deaths come amid other recent tragedies involving visitors to national parks and remote wilderness areas.
Earlier this month, a 68-year-old French tourist died after his vehicle became stuck in mud in Death Valley National Park, prompting him to set out on foot.
In Australia, an 18-year-old hiker was found dead in dense bushland in Nattai National Park after an eight-day search.
