Malcolm Young, one of the original members of AC/DC, has passed away.
He was 64 years old.
At this point, it's not clear what caused Malcolm's death, though we do know that he'd been suffering from dementia since at least 2014.
It was then that his family -- his brother Angus co-founded the band with him, and another Young brother, George, acted as a producer -- announced he'd be leaving the band due to his health issues.
In a statement released this morning, AC/DC wrote that "Today it is with deep heartfelt sadness that AC/DC has to announce the passing of Malcolm Young."
"Malcolm, along with Angus [Young, Malcolm's brother], was the founder and creator of AC/DC. With enormous dedication and commitment he was the driving force behind the band."
"As a guitarist, songwriter and visionary he was a perfectionist and a unique man," the statement continued. "He always stuck to his guns and did and said exactly what he wanted."
"He took great pride in all that he endeavored. His loyalty to the fans was unsurpassed."
In addition to the statement from AC/DC as a whole, Angus released one of his own.
"As his brother it is hard to express in words what he has meant to me during my life," he wrote, "the bond we had was unique and very special."
"He leaves behind an enormous legacy that will live on forever," he added.
"Malcolm, job well done."
Yet another statement was released by the rest of Malcolm's family -- they referred to him as "a songwriter, guitarist, performer, producer and visionary who inspired many."
"From the outset he knew what he wanted to achieve and, along with his younger brother, took to the world stage giving their all at every show."
"Nothing less would do for their fans."
Malcolm's death must have hit the Young family especially hard -- his older brother, George, passed away just last month.
His death will no doubt be tough for AC/DC fans, because after all, he was a huge, huge part of the band.
He and Angus formed AC/DC in 1973, and Malcolm played rhythm guitar all the way up until 2010 when they wrapped up their tour for their Black Ice album.
Black Ice, released in 2008, was also the last album on which Malcolm was credited as a songwriter.
Stevie Young, his nephew, replaced him in 2014 in time to record AC/DC's most recent album, Rock or Bust.
Our condolences to Malcolm's friends and family -- and, of course, all of his fans.