Credit: Michael Buckner/

Madonna is in mourning.

The pop star, 53, suffered a blow this week when her maternal grandmother, Elsie Mae Fortin, passed away at age 99 in Bay City, Michigan.

Fortin helped raise the singer after the sad 1963 breast cancer death of Madonna's mother (also named Madonna). Now a mother of four herself, Madonna was just five years old when her mom died.

According to the local Bay City News, the superstar and her grandmother were very close: she often visited, even staying with Fortin for several weeks during the summers.

In an e-mail statement, Madonna's longtime publicist Liz Rosenberg wrote, "I'm sorry, but Madonna will not be issuing any statements or conversing with the media regarding her grandmother. It is a totally personal matter to her."