St. Louis' fourth installment of State of Emergency: Heal the City kept its headliners a mystery till the last second. It was announced just a few days ago that Migos, Jeezy and Gucci Mane will perform at Chaifetz Arena Tuesday night at 8 p.m.

HiphopDX reports that the event was started in 2014 in the wake of the turmoil in Ferguson, a suburb of St.Louis. Demonstrations triggered by the death of Mike Brown at the hands of a police officer, turned into unrest as demonstrators seeking justice clashed with authorities. 

Local rapper Young Dip wanted to inspire unity in the community. He helped set up the show on March 14 to coincide with "314 Day." Borrowing its name from the city’s area code, the local holiday focuses on creating goodwill and a sense of community among its residents.

The event has since attracted a lot of big names in hip hop. Lil Wayne, Jeezy, 2 Chainz and Yo Gotti headlined last year's show.

State of Emergency 4 can be streamed tonight on REVOLT.tv and REVOLT TV.