Photo by Steve Jennings/FilmMagic

The hip-hop world is mourning the sudden death of up-and-coming rapper Juice Wrld. The 21-year-old Chicago-born rapper, real name Jarad Higgins, went into cardiac arrest and died early Sunday after an apparent accidental overdose of Percocet.

Percocet is a Schedule II narcotic that contains Acetaminophen (Tylenol) and the opioid oxycodone (OxyContin).

Federal agents were waiting inside a private hangar at Chicago's Midway Airport for the rapper's jet to arrive at 1:30 a.m. Agents reportedly received a tip from the pilot that the plane was loaded with drugs.

A search of the plane turned up 41 "vacuum-sealed" bags of marijuana, six bottles of prescription codeine cough syrup with no labels, two 9 mm pistols, a .40-caliber pistol, a high-capacity ammunition magazine and metal-piercing bullets, law enforcement sources told The Tribune.

No one in the rapper's entourage claimed ownership of the drugs and no charges were filed.

Higgins may have panicked and swallowed a handful of Percocets because the feds searched his private plane in November too.

Photo by Tony Forte/WENN

According to TMZ, customs agents conducted a search of a private plane on November 18 at LAX airport. Higgins was on his way to Sydney, Australia when his plane was searched.

via TMZ -- We're told drug-sniffing dogs were all over Juice and co. and their luggage. It's unclear if agents found anything -- we do know the plane was eventually allowed to take off with Juice on board.

TMZ broke the story ... Homeland Security agents, operating under an FBI task force, searched Juice WRLD's private jet early Sunday morning when it landed at Chicago's Midway Airport.