Tristan Thompson's Mom Andrea Dead After Heart Attack: Source

Tristan Thompson/Instagram Tristan and Andrea Thompson

Tristan Thompson's mother, Andrea Thompson, has died of a heart attack, a source confirms to PEOPLE.

Andrea died at her home in Toronto on Thursday. TMZ Sports was first to report the news on Friday afternoon.

Tristan flew to Toronto to be with his family, with ex Khloé Kardashian joining him to comfort and navigate him through the next few days, according to a source. Kardashian was close with Andrea, they add.

RELATED: Tristan Thompson Joins Daughter True for Sweet Dance Video: 'Anything for My Baby Girl'

Thompson shares True and a 5-month-old son, whose name has yet to be revealed, with Kardashian. He is also dad to 12-month-old son Theo with Maralee Nichols and 6-year-old son Prince with ex Jordan Craig.

George Pimentel/Getty Andrea and Tristan Thompson

Tristan last played in the NBA for the Chicago Bulls during the 2021-22 season. He has remained a free agent since parting ways with the team. Previously, he played for the Sacramento Kings and the Boston Celtics.

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In 2016, he helped the Cleveland Cavaliers defeat the Golden State Warriors for the NBA championship, alongside superstar LeBron James.