Answer
Pierre Nkurunziza, who served as President of Burundi from 2005 until his death in 2020, died of a heart attack on June 8, 2020. He was 55 years old. Nkurunziza's death was announced by the Burundian government, which said that he had died of "heart failure." Nkurunziza had been in poor health for several months, and had been hospitalized in April for treatment of a heart condition.