Mountain singer Leslie West has died at the age of 75.
The singer's heart "gave out" and he died on December 23 with his wife Jenni by his side.
Leslie's death was confirmed by his brother Larry West Weinstein, who said in a Facebook statement before his death that Leslie wasn't in a good way.
The musician had suffered from a cardiac arrest earlier in the week and was rushed to hospital but he did not regain consciousness.
"I am asking for all your prayers. [West’s wife] Jenni is by his side in Florida but it’s not looking good," his brother had written.
"Thanks Jenni, he wouldn’t have made it this far without you.
"His heart gave out and he’s on a ventilator. May not make it through the night."
The New York City native rose to fame in the hard rock band Mountain, and co-wrote their most famous track Mississippi Queen.
The group firmly cemented their spot in the rock hall of fame when they performed at Woodstock in 1969.
However, the band disbanded in 1972.
Despite the short tenure of the iconic band, Mountain reformed several times and their final album Masters Of War was released in 2007.
Leslie also went onto have a successful solo career and contributed to several albums such as Ozzy Osbourne's Under Cover.
His latest solo album Soundcheck was released in 2015.
As well as his contribution to music, Leslie had a regular appearance on Howard Stern’s radio show and even dipped into acting.
The star was considered one of the best rock guitarists of his time, but often downplayed his fame.
Speaking to Guitar World in 1987, he said: "I’m no great guitarist technically.”
"I only play with these two fingers [index and ring]. But you wanna know why people remember me? If you take a hundred players and put them in a room, 98 or 99 of ’em are gonna sound the same; the one who plays different, has some of his own, that’s the one you’re gonna remember.”
Leslie also battled poor health throughout his adult life, developing diabetes and having part of his right leg amputated as a result.
West is survived by his wife Jenni Maurer - who the star married onstage at a Woodstock anniversary show in 2009.
Tributes have flooded in for the artist since news of his passing.
Black Sabbath musician Geezer Butler took to social media to reflect upon Leslie's legacy.
"Sad to hear of Leslie West’s passing," he wrote. "Such a lovely bloke. He was fantastic to us when Sabbath supported Mountain on our first US tour. He came to see us at Mohegan Sun, even though he was wheelchair bound. Mississippi Queen one of, if not the, greatest riff of all time. RIP."
Rage Against The Machine star Tom Morello wrote: "Rest In Peace #LeslieWest. His guitar tone on ‘Mississippi Queen’ is hands down the BADDEST guitar tone on record."
