On the Vietnamese Tet holiday, Vietcong units sprang into action throughout South Vietnam, attacking more than 100 towns and villages with sapper commando units that were followed by waves of heavily armed troops.  The fighting created more than 500,000 refugees, and, while Vietcong deaths were some 37,000 with many more wounded or captured, the 2,500 American deaths in the assault dealt a crippling blow to public support of the war.