Authorities responded to Bennington's home in the 2800 block of Via Victoria in Palos Verdes Estates in the morning, where the singer was found hanged.
A source told Eyewitness News they were investigating Bennington's death as a suicide.
Bennington was close friends with the late rocker Chris Cornell and sang a rendition of Leonard Cohen's "Hallelujah" at his funeral. Cornell, 52, had committed suicide in May by hanging himself. The Soundgarden singer's birthday was also on July 20.
Like Cornell, Bennington battled drug and alcohol addiction at various times throughout his life.
His death sparked reactions from friends and fans all over the world. One fan even drove to Bennington's home to pay his respects, saying he believes Cornell's death hit the frontman hard.
Bennington's neighbor across the street said Bennington's death was unexpected. Dave Myers said the singer was a family man and seemed to do many activities with his kids.
Bennington's aunt and uncle stopped by the home and walked away in tears.
"Horrible. It's just devastating," his aunt said.
Bennington was with Linkin Park for almost two decades. The band, which started in Agoura Hills, gained fame with their debut album "Hybrid Theory" in 2000.
Linkin Park was also slated to appear in "Good Morning America's" summer concert series on Aug. 4 and play the Hollywood Bowl on Oct. 22.
Bandmate Mike Shinoda tweeted out his shock over Bennington's death and said the band would release a statement soon.
Shocked and heartbroken, but it's true. An official statement will come out as soon as we have one.— Mike Shinoda (@mikeshinoda) July 20, 2017
The band sold millions of albums with their unique mix of hard rock, hip hop and rap. In May, they released their seventh album "One More Light."
RIP Chester Bennington. Our hearts are heavy today. pic.twitter.com/rTunJvJebL— KROQ (@kroq) July 20, 2017
Cameron Strang, Warner Bros Records CEO and chairman, released a statement on behalf of the company.
"Chester Bennington was an artist of extraordinary talent and charisma, and a human being with a huge heart and a caring soul. Our thoughts and prayers are with his beautiful family, his band-mates and his many friends. All of us at WBR join with millions of grieving fans around the world in saying: we love you Chester and you will be forever missed."
The Recording Academy also released a statement saying the two-time Grammy winner had a "powerful range, paired with impressive songwriting skills."
"His riveting stage presence made every live performance magnetic, earning him millions of fans around the globe," the statement said, in part. "Having put as much passion into charitable causes as he did his musical craft, we were honored to pay tribute to him at our 2013 MusiCares MAP Fund benefit concert, where he lent his time and talents to help raise money to assist members of the music community with the addiction treatment process."
The Phoenix, Arizona native leaves behind his wife, Talinda Bentley, and six children.
IN MEMORIAM: Celebrities and notable figures who have recently passed away