Aretha Franklin, the musical icon known as the Queen of Soul, is "gravely ill," several members of her family told NBC affiliate WDIV-TV in Detroit.

"She is asking for your prayers at this time," WDIV-TV reporter Evrod Cassimy, who said he is a friend of the Franklin family, said in a tweet.

BREAKING NEWS: I am so saddened to report that the Queen of Soul and my good friend, Aretha Franklin is gravely ill. I spoke with her family members this morning. She is asking for your prayers at this time. I’ll have more details as I’m allowed to release. — Evrod Cassimy (@EvrodCassimy) August 13, 2018

Cassimy later tweeted that he had spoken to Franklin, who he said was "resting and surrounded by close friends and family."

Franklin, 76, the powerhouse vocalist behind hits like "Respect" and "Chain of Fools," announced in February 2017 that she would retire, saying she would perform at "some select things."

In the last year, Franklin canceled a series of concerts. Franklin told an audience in Detroit last summer: "Keep me in your prayers."

She did not perform at the New Jersey Performing Arts Center in Newark in March and did not appear at the New Orleans Jazz and Heritage Festival in April.

The singer's management team said in a statement in March that she had been ordered by her doctor to stay off the road and rest.