A 22-year-old passenger who suffered a medical emergency on a Southwest flight died after taking a new drug that has ravaged communities.

Rain McMillen Walmsley died on a flight from Dallas to Los Angeles on August 7. The Los Angeles Medical Examiner’s office concluded his cause of death was the combined effects of 7-Hydroxymitragynine and Mitragynine (7-OH) and ruled it an accident.

7-OH is a concentrated opioid-like product found in the kratom plant. It is occasionally marketed as kratom but is synthetic and contains higher levels of opioid-active alkaloids.