VIETNAM (CBS Newspath) -- On this day in history, January 30, 1968, Communist forces launched surprise attacks against South Vietnamese provincial capitals, marking the first day of the Tet (lunar new year).
U.S. troops battling Communist Forces during the Tet Offensive. (U.S. Army photo/file)
The "Tet Offensive" was the heaviest and most coordinated Communist aggression of the war.
Over 30 provincial capitals were hit as well as several US and South Vietnamese airfields and bases.
An estimated 21,330 Communist troops and 1,169 allied soldiers were killed over the next few days.
Despite the magnitude of the surprise attack, American marines were able to roll back some of the Viet Cong's gains within weeks.
The Vietnam Peace Accord was signed in Paris five years later.