Heavy D died from a pulmonary embolism caused by deep leg vein thrombosis on November 08, 2011.
TMZ reports: “…and a long flight back to L.A. from a Michael Jackson memorial concert may have been a contributing factor. A pulmonary embolism is a blockage of one or more arteries in the lungs — most often caused by blood clots which travel into the lungs from other parts of the body. In Heavy’s case, the clot was formed in his legs. Officials from the L.A. County Coroner’s Office say Heavy also suffered from heart disease, which could have been a contributing factor in his death.”
There were earlier reports of the rapper having pneumonia. He was 44 years old.