Two men have been arrested at Midway Airport in Chicago for attempting to smuggle 44 pounds of fentanyl in their checked luggage.
The suspects, identified as 24-year-old Robert Louis and 26-year-old Jameer Hollingshed, had flown in from Los Angeles with the fentanyl packed in their bags.
The drugs were reportedly concealed in pant legs and sweatshirts and had a street value of $3.1 million.
The bust was carried out by federal agents with the Drug Enforcement Administration (DEA).
It is unclear at this time what charges the suspects will face.
Fentanyl is a synthetic opioid that is up to 100 times more potent than morphine and has been responsible for a surge in overdose deaths in recent years.