RB Leipzig issued a statement on the club's official website: "A heartbreaking night.
"There was a medical emergency in the home area today before the game between RB Leipzig and Borussia Mönchengladbach and the person unfortunately died in the stadium.
"On the same day, a member of the Borussia Mönchengladbach fan scene died in a traffic accident on the way to Leipzig.
"We are deeply saddened and all our thoughts are with the fans' families and relatives, to whom we express our deep condolences and sympathy.
"Rest in peace."