Rain McMillen Walmsley’s cause of death has been ruled an accidental kratom overdose, according to Los Angeles County officials.
The 22-year-old passenger died mid-air during a Southwest Airlines flight from Dallas to Los Angeles in August, and the LA County Medical Examiner’s Office has now determined the specific substances responsible. Walmsley’s death resulted from the “combined effects of 7-Hydroxymitragynine and Mitragynine,” compounds found in the plant supplement kratom, with his manner of death officially listed as an accident.
The flight was bound for Los Angeles International Airport when the medical emergency unfolded. Walmsley was among travelers on the routine domestic route connecting Texas to California, a corridor Southwest serves heavily. The incident prompted the aircraft to continue to its destination, where authorities met the plane and launched their investigation.
Kratom has drawn escalating scrutiny from health officials and regulators as overdose cases linked to the substance have mounted nationwide. The supplement, derived from a tropical tree native to Southeast Asia, contains psychoactive compounds that produce effects ranging from stimulant-like at low doses to sedative at higher amounts. The two compounds cited in Walmsley’s death, 7-Hydroxymitragynine and Mitragynine, represent kratom’s primary active alkaloids.
Federal agencies have grappled with how to classify and regulate kratom amid rising use. The Drug Enforcement Administration has previously moved to schedule the substance as a controlled drug, only to withdraw that proposal following public pushback. The Food and Drug Administration has issued repeated warnings about kratom’s potential for abuse, addiction, and death, though it remains legally available in most states under varying degrees of restriction.
California maintains relatively permissive kratom laws compared to some jurisdictions. Several states and municipalities have enacted outright bans, while others have implemented age restrictions or labeling requirements. The patchwork regulatory landscape has left consumers with inconsistent protections and product quality standards.
Walmsley’s case marks a rare instance of an in-flight fatality attributed specifically to kratom toxicity. Aviation medical emergencies more commonly involve cardiac events, respiratory distress, or other acute conditions. The confined environment of commercial aircraft, with limited medical equipment and personnel, presents distinct challenges for responding to such crises aloft.
Southwest did not immediately detail what medical assistance crew members or any onboard health professionals may have rendered during the emergency. Airlines typically equip flights with basic first aid supplies and automatic external defibrillators, and can consult with ground-based medical advisory services via radio or satellite communications.
The LA County Medical Examiner’s findings bring closure to the formal investigation into how a young passenger died during what should have been a routine cross-country journey. Walmsley was 22.