Tito Jackson suffered a medical emergency at a New Mexico shopping centre shortly before he died on Sunday.
In a statement issued on Monday, the Jackson 5 star's three sons confirmed their father had passed away suddenly. Jackson was 70.
And according to a press release from officials at the Gallup New Mexico Police Department obtained by People, the musician fell ill at the American Heritage Plaza on US Highway 491 in Gallup on Sunday evening.
A police officer was notified that there was "an individual requiring medical attention and promptly requested an ambulance".
Jackson was then transported to a local hospital, where he was pronounced dead.
Before his death, the singer had been touring with brothers Jackie and Marlon as The Jacksons.
They performed on 8 September at the Boogietown Festival in Walton-on-Thames in Surrey, England and had U.S. gigs planned for Atlantic City and Cincinnati over the next few weeks.
In light of the sad news, Boogietown organisers posted, "We are incredibly saddened to hear about the passing of Toriano Adaryll (Tito) Jackson, and send our love and condolences to his family at this difficult time. Thank you for the many years of music and inspiration."
A cause of death was not listed in the police report. The preliminary investigation is ongoing.