Three U.S. Marines found dead in a vehicle outside a convenience store in Hampstead, North Carolina on Sunday died from carbon monoxide poisoning, according to autopsies performed by the Pender County medical examiner.

Marine Corps Lance Cpl. Merax C. Dockery, 23, from Pottawatomie, Oklahoma, Marine Corps Lance Cpl. Ivan R. Garcia, 23, from Naples, Florida, and Marine Corps Lance Cpl. Tanner J. Kaltenberg, 19, from Madison, Wisconsin were found outside a Speedway in Hampstead after Dockery's mother called Camp Lejeune because he didn't arrive on a scheduled flight Saturday night.

Police then pinged Dockery's phone and found the three men dead.

There were no signs of foul play, according to the Pender County Sheriff's Office.

Tragic loss

"My deepest sympathy and condolences are extended to the family, friends and colleagues of Lance Cpl. Kaltenberg, Lance Cpl. Dockery and Lance Cpl. Garcia,” Brig. Gen. Michael E. McWilliams, commanding general of the 2nd Marine Logistics Group, said in a press release. “Our focus is providing the necessary resources and support to those impacted by their tragic loss as they navigate this extremely difficult time.”

Garcia entered active duty in July 2019, Dockery in June 2020 and Kaltenberg in May 2021, the Marine Corps said.

The men were motor vehicle operators with the Combat Logistics Battalion 2, Combat Logistics Regiment 2 and 2nd Marine Logistics Group at Camp Lejeune, said First Lt. Raymond Fullbright, of the 2nd Marine Logistics Group.

“I am saddened by the timeless and tragic death of these three young men, who served our country honorably," Pender County Sheriff Alan W. Cutler said in a statement. "Our thoughts and prayers remain with their families and colleagues during this time.”

Accident or suicide

The circumstances of the mens' deaths could have been accidental or intentional by suicide, but no information is available about what exactly happened.

It only takes a few minutes for a car with a blocked tailpipe to fill up with harmful levels of carbon monoxide, but such an occurrence in the summertime when there is no risk of snow blocking a tailpipe, this is a rare occurrence.

Pender County Sheriff's office is investigating what could have caused the deaths and may be able to give more information after checking the condition of the vehicle.

Either way, the deaths are unspeakably tragic.

Military suicides

If it turns out to have been suicide, the men would join the more than 500 military members each year who take their own lives. Veterans have even higher rates of suicide.

The military has been criticized for not providing adequate mental health services to its active duty member and veterans, who often experience traumatic events in combat.