The iconic Mary Wilson, a co-founder of the Supremes and the longest-running member of the hugely influential Motown group,  is dead at 76.

According to a statement from publicist Jay Schwartz, as reported by the Associated Press early Tuesday morning, Wilson died at her home in Las Vegas, Nevada on Monday night. At the time of this writing, the cause “was not immediately clear,” per the publicist. 

Wilson was joined by Diana Ross, Florence Ballard, and Betty McGlown in the original version of the Supremes. She remained in the group, which saw several lineup changes during its globally popular run, until its disbandment in 1977.

Monday morning, Ross told fans she had just woken up to the news and offered condolences to Wilson’s family.

“I am reminded that each day is a gift,” she said. “I have so many wonderful memories of our time together. The Supremes will live on in our hearts.”

In a video shared to her YouTube channel over the weekend, Wilson revealed that she had recently had discussions with Universal about giving a proper modern release to classic recordings including her solo “Red Hot”-featuring eponymous 1979 album.

“Well, this is Black History Month, yes indeed it is, and I am just so thrilled because so much has happened to me in the month of February,” Wilson said in the video, seen below. “I mean, really! I’m not saying me. I mean the Supremes, you know, and so we’re gonna be talking about the Supremes’ 60th anniversary and I will be talking a lot about that. And mainly because I finally have decided how to work with Universal and they are going to release new recordings, Mary Wilson recordings.”

In a statement to Variety, Berry Gordy—founder of the Motown label—said he was “shocked and saddened” to hear of Wilson’s death.

“I was always proud of Mary,” Gordy said. “She was quite a star in her own right and over the years continued to work hard to boost the legacy of the Supremes. Mary Wilson was extremely special to me. She was a trailblazer, a diva and will be deeply missed.”

RIP.