Timbuk2 was the name given to an otherwise unnamed village in the Echo Sector of Củ Chi District in Vietnam. In early 1970, three infantrymen including Al Crofton were sent into the tunnel to blow it up. Two of them came out, but Crofton was left inside and was killed by the Viet Cong. Harry Bosch and Billy Meadows were then sent in to find Crofton. This was Bosch's last tunnel in Viet Nam, and he has photos of himself and Meadows at the Tumbuk2 tunnel.