On 19 October 1986, President Machel died when his presidential aircraft crashed near South Africa's border under mysterious circumstances. A South African sponsored investigation alleged that the crash was caused by errors made by the flight crew, a conclusion that was not universally accepted. Subsequent investigations have failed to reach a conclusion and the accident remains surrounded by conspiracy theories. Machel's successor was Joaquim Alberto Chissano, who had served as foreign minister from 1975 until Machel's death. Chissano continued Machel's policies of expanding Mozambique's international ties, particularly the country's links with the West, and starting programs of internal economic and military reforms.