Chicago rapper Lil Jojo was killed Tuesday night when a gunman sprayed bullets at him while he rode his bicycle. After the news broke, rival rapper Chief Keef took to Twitter to mock Jojo's demise, starting a social media war tha continues the feud the rappers had in life, according to GlobalGrind.com.

Jojo, whose real name was Joseph Coleman, was just 18 years old when he was shot to death on Chicago's south side Tuesday night, according to the Chicago Tribune. No arrests have been made in the shooting, but police said the killer opened fire from either a tan or grey vehicle. They also were investigating whether the killing was gang-related.

Jojo recently released a song called "3hunna K," which aimed to diss Chief Keef and fellow rapper Lil Reese. Just a few days ago a video was uploaded to YouTube with Reese and Chief Keef embroiled in a heated argument with Lil Jojo, according to the Smoking Section. During the argument someone audibly yelled, "I'mma kill you."

You can find that video by clicking here.

In a series of tweets on Tuesday night, Chief Keef made it clear he wasn't mourning Jojo's death.

Its Sad Cuz Dat Nigga Jojo Wanted To Be Jus Like Us #LMAO

— CampaignSosa300 (@ChiefKeef) September 5, 2012

hahahahahhahahahahahahahaahhAAHAHAHAHA #RichNiggaS***

— CampaignSosa300 (@ChiefKeef) September 5, 2012

The classless move on social media was criticized by many, with some on Twitter threatening to kill Chief Keef himself. On Wednesday afternoon the rapper claimed his account had been hacked.

This news follows comments from mainstream rapper Lupe Fiasco that people like Chief Keef made him fear for the future, especially in Chicago.

"Chief Keef scares me. Not him specifically, but just the culture that he represents," Fiasco said according to HipHopDX. "Specifically in Chicago. And I don't speak this about any other city because I'm not from there. But like my family lives in Chicago. So my nephews, my cousins, my friends, and my peoples they all in those hoods that he represents.

"When you drive through Chicago...The hoodlums, the gangsters, and the ones you see killing each other. And the murder rate in Chicago is skyrocketing and you see who's doing it and perpetrating it, they all look like Chief Keef."

Chief Keef responded to Fiasco's comments by threatening him on Twitter.