[1]: 5–341 The 1st Cavalry Division built a runway capable of landing de Havilland Canada C-7 Caribou aircraft at the base in early April.

[5] LZ Bronco at Duc Pho became the base camp for Task Force Barker, an element of the 11th Brigade, Americal Division by 1968.

One contributor to My Lai was the difficulty of distinguishing between civilians and VC infiltrators, and another was combat stresses created by events that followed the Tet offensive, including a situation where Lt. Calley's platoon was ordered to cross a known minefield before it had been cleared.

Another was orders developed from apparently vague or even faulty intelligence indicating that My Lai was a Viet Cong stronghold.

Brief personal discussion with retired Col. Jim Tynan, who served on the board of inquiry the Army established after My Lai became public