Scott Weiland, the ex-frontman of Stone Temple Pilots and Velvet Revolver who battled substance abuse over the years, was found dead on Thursday. He was 48.

Jane’s Addiction guitarist Dave Navarro first reported the news on Twitter. “Just learned our friend Scott Weiland has died. So gutted, I am thinking of his family tonight,” Navarro wrote.

Weiland was found unresponsive on his tour bus in Minnesota, where he and his current band The Wildabouts were scheduled to perform at the Medina Ballroom, but the show was cancelled, according to TMZ.

It’s unknown what caused the singer’s death.

Weiland, who battled heroin and cocaine addiction over the years, was known for his flamboyant and unpredictable persona onstage.

Wielding a megaphone alongside his bandmates for sound effect, the fiery-haired frontman led the Southern California-based Stone Temple Pilots for two decades.

Also known as “STP” by their fans, the quartet first broke out in 1992 with hit single “Creep” before going on to become one of the most popular rock bands of the 1990s and 2000s with power ballads like “Plush,” “Big Empty” and “Interstate Love Song.”

Their music still plays in heavy rotation on alternative rock stations alongside ’90s grunge acts Nirvana, Soundgarden and Pearl Jam.

But it was Weiland’s rock star ways that often got him in trouble offstage.

After spending five months in prison for possession of heroin in 1998, he was later charged with domestic abuse for assaulting his wife.

In 2008, he checked into rehab after being arrested for a DUI and once, after a fight with his wife, leapt from a moving car to score heroin.

“People have this misconception about me,” he said in an interview with USA Today in 2011. “OK, I struggled with heroin and cocaine and I was a big rock star. But music is not what defines me. I’m a brother, a father, a son.”

Weiland later split from Stone Temple Pilots and formed supergroup Velvet Revolver with ex-Guns N’ Roses rockers Slash and Duff McKagan, and Matt Sorum. The band eventually split up, again because of Weiland’s substance abuse.

“I’m still on the verge all the time,” he said of his fight to remain sober. “My brother passed away [from a drug overdose in 2007], and that’s something that will always stay with me.”

In 2008, Weiland reunited with STP for the last time before leaving the band again and embarking on a solo career. But not, of course, without Weiland storming off in dramatic fashion.

After ex-members of Stone Temple Pilots sued the two-time Grammy-winner in 2013 for playing their material during his solo shows (STP was later fronted by Linkin Park singer Chester Bennington), Weiland countersued, calling his ex-bandmates’ claims “ridiculous.”

The group eventually reached a settlement out of court.

“I apologize to those fans out there who are, feel like they’re caught in the middle of it,” he said at the time. “‘Cause I sure feel like I’m caught in the middle of it emotionally, and all I want to do is play music.”

Known for his baritone vocal style, Weiland has also performed with the remaining members of The Doors for a VH1 “Storytellers” special.

He is survived by his two children, Noah and Lucy.