Answer
The demise of Peter Mutharika's elder brother occurred on April 5, 2012. Bingu wa Mutharika, the former President of Malawi, succumbed to a heart attack while in office. His unexpected passing left the nation in a state of mourning and political uncertainty. This tragic event paved the way for Joyce Banda, the Vice President, to assume the presidency, marking a significant moment in Malawi's history.