The police of Gallup, New Mexico, has released details of the events that unfolded in the hours leading up to the death of Tito Jackson on Sunday night. The musician suffered a medical emergency near the American Heritage Plaza shopping center before being transported to a local hospital, where he was later pronounced dead at the age of 70.

According to a statement from Gallup police, an officer stationed near the mall requested an ambulance after being notified of a person requiring immediate medical attention. “The individual was subsequently transported to a local hospital in Gallup, NM, where he was pronounced deceased,” the statement said. “Afterward, the hospital requested the attendance of detectives and the medical examiner’s office.”

Jackson was on a road trip at the time. The exact cause of death is not yet known, and the preliminary investigation is still ongoing. “Investigators are actively interviewing witnesses and examining both physical and electronic records,” the police department said. “The department’s understanding of the facts and circumstances may evolve as additional evidence is collected and analyzed.”

Jackson’s three sons – Taj, Taryll and TJ – released a joint statement on social media on Monday about their father’s death. “We are shocked, saddened and heartbroken,” they wrote. “Our father was an incredible man who cared about everyone and their well-being.”

Earlier this month, Jackson performed for the last time in Surrey, England, with his brothers Jackie and Marlon. Before returning to America last week, the musicians visited a memorial in Munich, Germany, dedicated to their late brother Michael. “We are deeply grateful for this special place that honors not only his memory, but our shared legacy,” Jackson wrote on Facebook. “Thank you for keeping his spirit alive.”

Jackson was born Toriano Adaryll Jackson on October 15, 1953 in Gary, Indiana. He recently moved to Tulsa, Oklahoma. The musician leaves behind his brothers Jermaine, Randy, Marlon and Jackie, his sisters Janet, Rebbie and La Toya, and his mother Katherine.