Union Berlin have confirmed their former coach Sascha Lewandowski, who also managed Bayer Leverkusen, has died at the age of 44.
Having been promoted from a role with the youth team, he coached Leverkusen's senior side jointly with Sami Hyypia from April 2012 to May 2013 and served as interim head coach when the former Liverpool defender left the club in April 2014.
He took over at Union Berlin in September last year but stepped down in March on the advice of doctors after being diagnosed with acute fatigue syndrome, a severe form of burnout that led to heart problems.
"We are deeply shocked and incredibly sad," Union Berlin president Dirk Zingler said in a statement.
"Our sincere condolences and our deepest sympathy to the family and relatives of Sascha Lewandowski."