He had been admitted in Delhi 's All India Institute of Medical Sciences a few days previously with chest neurological problems and died of a heart attack .
Singh died on 4 March 2011 , at the age of 80 .
Singh had been admitted in Delhi 's All India Institute of Medical Sciences a few days previously with chest neurological problems and died of a heart attack .
Singh died on 4 March 2011 , at the age of 80 .