READ: Mike Shinoda’s Statement on Chester Bennington’s Death

Getty Musicians Chester Bennington, left, and Mike Shinoda of Linkin Park perform onstage during Rock in Rio USA at the MGM Resorts Festival Grounds on May 9, 2015.

The unexpected death of Linkin Park frontman Chester Bennington has left many fans and musicians in the industry stunned and saddened.

Bennington, who had been the lead vocalist in the band since the late 1990s, committed suicide by hanging, TMZ reported Thursday.

Among those who have been left shocked at his passing is one of his best friends and former bandmate, Mike Shinoda.

Shinoda, the co-vocalist and founder of the band, sent out a tweet following the news saying he is “heartbroken.” He promised to release a full statement later in the day.

Shinoda founded the band in 1996 alongside Rob Bourdon and Brad Delson. They brought on three other band members and were first called Xero, though they had a tough time obtaining a record deal. That’s until he recruited Bennington to come along and be the lead vocalist.

Once Bennington joined the band, now called Linkin Park, they landed a deal with Warner Bros Records and released one of the most popular rock albums of the 2000s, Hybrid Theory. The album found international success and achieved Diamond status by the RIAA in 2005.

Mike Shinoda Praises Chester BenningtonMike Shinoda praises Chester Bennington as one of the best singers of our time. All rights reserved to Linkin Park, and their rightful owners. I do not own any of this content.2012-05-29T00:16:29.000Z

Through all of the success, Bennington had a well-documented struggles with drugs and alcohol.

In 2014, Shinoda told the British newspaper Metro that the band would often come together to support Bennington in his battle against the substances.

“When Chester had some problems, everybody jumped up to help him and tell him how supportive we wanted to be and how much it means to us that he was doing something positive,” Shinoda told the publication.

Bennington told Teamrock.com that when he was a child, he was molested by an older friend, which destroyed his confidence and led to extensive drug use. He also said he would often have suicidal thoughts.

“I’ve done everything, I got really, really bad,” Bennington said of his drug usage. “When I was 13 to 16, I was doing a ton of LSD and a lot of drinking. Then, when we couldn’t find acid, we turned to speed. I got really bad, really quickly.”

The thing that kept Bennington together was the close chemistry in the band, Shinoda said to Metro.

“The band got so big so fast it was obvious to us when people were trying to take advantage,” Shinoda said. “We knew we couldn’t trust some of these people but we could trust each other.

“We’re lucky to have a band full of guys who have their head screwed on straight. A lot of life experience goes into that, but we just support each other; we have each other’s back. At the end of the day we love what we do. We’re not willing to throw that away on anything.”

In a 2015 interview before a show, Shinoda talked about his relationship with Bennington and the band, saying that it’s always changing. But no matter what, they’ve always remained close.

“What’s really weird to contemplate is in the very beginning we didn’t know Chester that well … Chester joined the band in the late 90s and by the time we made the first record, we had known each other a few years but it’s not like I knew him since I was 13,” Shinoda said during the interview. “Over the course of that time, we got tighter and tighter and part of that’s just knowing what we’ve created together and respecting each other’s heart in making that a reality.”