Lil Durk's Brother, OTF DThang, Dead at 32 After Reportedly Being Shot

Lil Durk's older brother, OTF DThang, died this weekend ... TMZ has confirmed.

Cook County officials tell us Dontay Banks Jr. -- DThang's government name -- was found deceased on the 7900 block of S. Loomis Blvd. in Chicago, and has been assigned a case number. An autopsy still has to be done to figure out the cause and manner of death.

Reports say DThang was shot in the head outside of a nightclub and died on the spot ... citing alleged witnesses who say they saw the shooting go down.

DThang was a rapper himself ... but wasn't nearly as big as Durk is, who's blowing up right now. Still, he's got a string of songs out -- although it doesn't look like they ever collab'd.

This is just the latest tragedy to strike Durk's inner circle -- he's lost a handful of friends and loved ones over the years ... including, famously, the death of his labelmate King Von ... who was shot and killed last year. A producer he worked closely with named Turn Me Up Josh also died just last week ... something Durk himself commemorated with a post.

Durk hasn't commented on his brother's passing yet, but condolences have been pouring in all over social media. DThang was 32.