Country music icon Merle Haggard died on Wednesday -- the same day as his 79th birthday -- at 9:20 a.m. at home near Redding, California, his manager confirmed to ET.
Haggard was reportedly diagnosed with pneumonia last year, and canceled a series of scheduled shows in recent months in an effort to recover from the illness.
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"Two-time GRAMMY Award winner and 2006 Recording Academy Lifetime Achievement Award recipient Merle Haggard was an uncommon hero in country music," a statement from Neil Portnow, President/CEO of The Recording Academy, read. "An exceptional multitalented singer/songwriter, guitarist, and fiddler, Merle's massive success was rooted in his masterful ability to celebrate the outlaws and the underdogs."
"Merle's extraordinary talent resulted in more than 30 No. 1 country hits and his remarkable performances will forever live on and inspire music creators worldwide," the statement continued. "We have lost an innovative member of the music community and our sincerest condolences go out to Merle's family, friends, collaborators and all who have been impacted by his incredible work. He will truly be missed."
Many of Haggard's fellow country stars also released statements, including Dolly Parton, who wrote, "We've lost one of the greatest writers and singers of all time. His heart was as tender as his love ballads. I loved him like a brother. Rest easy, Merle."
"Merle Haggard was an original," a statement from Hank Williams, Jr., read. "Not just a singer, not just a songwriter, not just another famous performer. He was your common everyday working man. I remember when I was 15 years old on tour with Waylon Jennings and Merle Haggard. They both were wondering which one of the two was going to make it. Well, they both made it. Today, ole Merle joined Waylon, George, and daddy to sing in the Heavenly choir."
A statement from Big & Rich's 'Big Kenny' Alphin echoed Parton and Williams' sentiments. "We join the world of the broken hearted hearing of the death of Merle Haggard," it read. "One of the first things John and I realized we had in common was our love of Haggard songs. What a blessing to have had a chance to get to know him and work with such a legend in our career. Merle, guess you finally are on the ultimate Natural High. We will have your music in our hearts and souls and honkytonk nights forever! God Bless the great Merle Haggard. May you fly with the Angels."
The legendary musician was best known for helping with the growth of the outlaw country movement in the '70s, as well as his chart-topping hits, including "Okie from Muskogee," "Big City" and "Mama Tried," which later led to his induction into the Country Music Hall of Fame in 1994. In 1970, he became the first artist to receive the Triple-Crown Award from the Academy of Country Music. Since then, only five country stars have received the honor. The ACMs honored him again in 2014, presenting Haggard with the Crystal Milestone award.
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Before he began creating catchy tunes, Haggard made headlines in 1957, when he was arrested and spent two years and nine months behind bars at the San Quentin State Prison in California after attempting to rob a roadhouse in Bakersfield, California. While he was locked up, he began his music career with the prison’s country music band, crediting a 1958 performance for inmates by Johnny Cash as his main inspiration.
Upon hearing the news on Wednesday, family, friends and fans of Haggard's took to social media to pay their respects to the late country star.
Over the weekend, ET's Nancy O'Dell chatted with Miranda Lambert backstage at the Academy of Country Music Awards in Las Vegas, where she revealed two country artists on her "dream collaboration" bucket list -- Dolly Parton and Haggard.
"You got anyone left on your bucket list?" O'Dell asked, in which Lambert replied, "Merle Haggard, for sure."
Hear more in the video below.