A local North Carolina sheriff's office said that three Marines found dead in a car outside Camp Lejeune on Sunday morning died of carbon monoxide poisoning.
In an update posted to social media Wednesday, the Pender County Sheriff's Office said autopsies found that "all three deaths are consistent due to carbon monoxide poisoning."
The sheriff's office did not specify how the Marines were exposed to the deadly gas.
The three Marines, who were identified by the Corps on Tuesday, were all motor vehicle operators with Combat Logistics Battalion 2, Combat Logistics Regiment 2, 2nd Marine Logistics Group. They ranged in age from 19 to 23 years old.
According to the sheriff's office, deputies received a call at around 8 a.m. Sunday morning from a mother whose son was stationed at Camp Lejeune, saying that "he had failed to arrive on a flight in Oklahoma the night prior."
The mom told the sheriff's office that "she had spoken with a supervisor in his unit and that someone was en route" to the Speedway Convenience Store to see whether they could find the missing Marine.
Although the sheriff's statement does not identify the caller, Lance Cpl. Merax C. Dockery, 23, was identified as one of the dead Marines. According to the Marine Corps, Dockery was from Pottawatomie, Oklahoma.
When the mother called the office, the deputies were already "working a separate missing person report," the statement noted.
About 40 minutes later, at around 9 a.m., "a second call was received by Pender County Sheriff Communications indicating that the missing person had been located at the Speedway and that he, along with two other Marines, were deceased inside of a vehicle parked at the location."
Sheriff Alan W. Cutler said in a statement that he was "saddened by the timeless and tragic death of these three young men, who served our country honorably."
The other two Marines were identified as Lance Cpl. Tanner J. Kaltenberg, 19, from Madison, Wisconsin, and Lance Cpl. Ivan R. Garcia, 23, from Naples, Florida.
-- Konstantin Toropin can be reached at email@example.com. Follow him on Twitter @ktoropin.