The legendary George Jones passed away last Friday (April 26) at the age of 81, leaving behind a towering musical legacy of more than five decades. Now, the iconic entertainer's cause of death has been revealed.

Medical Daily reports that Jones died of hypoxic respiratory failure, a condition that occurs when there is too little oxygen present for the body to carry out its basic functions. Hypoxic respiratory failure can result from low oxygen levels in the blood, an inefficient blood supply to the tissues, or the presence of toxins which prevent cells from using the oxygen that is present.

Jones had been in the hospital repeatedly throughout 2012 and early 2013 with various upper respiratory infections, having to cancel and re-schedule a number of planned concerts. He had been hospitalized since April 18 with a fever and irregular blood pressure.

The singer was embarked on what was planned to be his final tour, with a career-spanning all-star farewell concert scheduled for Nashville on November 22. His funeral is slated for Thursday (May 2) at the Grand Ole Opry House in Nashville, where friends, family and music industry giants will gather to pay tribute to the enduring legacy of one of country music's greatest vocalists. The service will be open to the public.

In lieu of flowers, Jones’ family has asked that contributions be made to the Grand Ole Opry Trust Fund, or the Country Music Hall of Fame and Museum.

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