The Cook County Medical Examiner said the rapper, born Jarad Higgins, died as a result of an accidental overdose on oxycodone and codeine.
Higgins died after suffering cardiac arrest at a private hangar at Midway Airport in December, authorities said. He reportedly had a seizure.
Chicago police said they were called to Midway Airport to assist federal authorities just after 1:30 a.m. on Sunday, Dec. 8, after a private jet arrived at the airport they said contained a large quantity of narcotics.
Police said the plane's occupants were in the lobby with their luggage in two carts. K9 units from the Illinois State Police searched the luggage, and alerted officers to narcotics in two of the suitcases. Police said a search of the luggage turned up 41 bags of suspected marijuana and six prescription bottles of suspected liquid codeine, as well as three guns.
Police said none of the occupants of the plane would claim ownership of the luggage.
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Police said it was during this time that Higgins suffered a medical emergency, which they described as a seizure. Police said a Homeland Security officer administered Narcan, but he was later pronounced dead.
A private funeral for family was held on Dec. 14 in Harvey. Fans held a memorial service the same night at the Bean in downtown Chicago.
Two men with Juice WRLD's entourage, one of whom identified himself as private security, were arrested and charged with misdemeanor gun offenses.
Higgins grew up in Chicago's south suburbs and graduated from Homewood Flossmoor High School in 2017.
He rose to fame off the back of his 2018 album "Goodbye and Good Riddance," which peaked at No. 6 on the Billboard 200. The lead single "Lucid Dreams" peaked at No. 2 on the Billboard Hot 100. He also won the "Top New Artist" Billboard award in 2019.