 The operational plan for the General Offensive and Uprising had its origin as the " COSVN proposal " at Thanh 's southern headquarters in April 1967 and had then been relayed to Hanoi the following month . The general was then ordered to the capital to explain his concept in person to the Military Central Commission . At a meeting in July , Thanh briefed the plan to the Politburo . On the evening of 6 July , after receiving permission to begin preparations for the offensive , Thanh attended a party and died of a heart attack after drinking too much . 
