Johnny Cash, one of country music's most iconic figures, has died at the age of 71.
Cash died at Baptist Hospital in Nashville, Tennessee, "due to complications from diabetes, which resulted in respiratory failure", said Lou Robin, his manager.
The announcement shocked fans, who had been relieved to hear that Cash had been released from hospital on Tuesday after three weeks of treatment for an inflammation of the pancreas.
Although Cash had been hospitalised frequently over the past several years with pneumonia and other respiratory ailments, Mr Robin had described his recent treatment as an "isolated incident".
Arkansas-born Cash was one of the most imposing and influential figures in post-World War II country music. With his deep resonant baritone and spare, percussive guitar, he had a basic, distinctive sound which blended country, folk and rock and roll.
Indeed, starting out in the 1950s following a spell in the US Air Force during the Korean War, Cash's career coincided with the birth of rock and roll and his rebellious attitude and direct self-taught approach to music shared a lot of similarities with that medium, winning him many admirers from the rock arena, ranging from Bob Dylan in the 1960s to U2 in the 1990s.
Cash stood out from his country peers. He made his Grand Ole Opry debut in 1957, appearing all in black while other performers were decked out in flamboyant, rhinestone-studded outfits, earning him the nickname "The Man In Black".
During the 1950s and 1960s Cash became one of country music's biggest stars, scoring well over 100 hit singles, including "Walk the line" and "Don't take your guns to town".
But his success was frequently marred with excess as drinking bouts and an addiction to amphetamines encroached on his music-making. Following occasional brushes with the law, once for starting a forest fire, Cash was arrested in 1965 for attempting to smuggle amphetamines into the US in his guitar case.
Banned from the Opry and divorced by his first wife, Cash's salvation arrived in the guise of country singer June Carter, who had previously written one of his biggest hits "Ring of Fire".
With Carter's help he embraced fundamentalist christianity, shook his addictions and recorded some of his most popular records, including two sets recorded live in front of prisoners at Folsom and San Quentin and his only top ten pop hit, "A boy called Sue". Between 1969 and 1971 he hosted his own television show.
Meanwhile, Cash had married Carter after he proposed live on stage. Their marriage was to last until Carter's death at 73 in May this year.
Through the 1970s and 1980s Cash's frequency on the country charts gradually declined, although his enormous influence was reflected by becoming the youngest inductee into the Country Music Hall of Fame in 1980.
Cash became something of a cult figure in the 1990s and 2000s as influential rock artists such as Bono and Nick Cave cited him as a major inspiration. His recent series of "American" albums had drawn a strong critical reception. Cash was set to complete a new album, tentatively entitled "American V", next week.