Cause of death revealed for 22-year-old who died on LA-bound Southwest flight

The cause of death for a 22-year-old man who died aboard a Southwest flight in August has been revealed.

Rain McMillen Walmsley died from the “combined effects of 7-Hydroxymitragynine and Mitragynine,” according to the Los Angeles County Medical Examiner’s Office. His manner of death is listed as an accident.

7-Hydroxymitragynine and Mitragynine are compounds found in kratom, a plant supplement that has drawn growing concern due to recent overdoses.

Kratom comes from a plant native to Southeast Asia, whose leaves are typically dried and consumed for their stimulant or sedative effects, depending on the dosage. In smaller amounts, the substance can produce effects similar to caffeine.

But 7-Hydroxymitragynine, or 7-OH, can produce opioid-like effects when its concentration is artificially increased. Kratom is sold widely, but is legal and unregulated. There’s been recent scrutiny about a high risk of abuse of the drug.

Walmsey was aboard Southwest Airlines Flight 958 on August 7. The flight was traveling from Dallas to Los Angeles when Walmsey suffered a medical emergency and stopped responding.

Crew members and fellow passengers attempted to save him, with multiple CPR attempts carried out while the plane continued toward Southern California.

Emergency responders were waiting for the aircraft when it landed at Los Angeles International Airport, but their efforts were unsuccessful.

Paramedics were unable to revive Walmsey, and firefighters pronounced him dead at the scene.

Southwest Airlines previously confirmed that there had been a “medical incident involving a customer” aboard Flight 958 but did not provide additional details about the passenger.

The Irvine City Council, concerned with adverse effects from kratom, recently imposed stricter regulations on the sale and distribution of synthetic kratom. Officials restricted its use to customers 21 and older and established potency limits, banning the sale and distribution of kratom products containing more than 2% 7-OH.

In Mississippi, two college students in separate incidents were found dead with kratom at the scene in September, inflating concern to even higher levels. The Lafayette County Metro Narcotics squad previously said it does “not have confirmed information indicating that kratom or any other substance was a contributing factor in either death.”

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