the United States Army Military Intelligence Corps to be a Viet Cong stronghold. Army intelligence concerning the presence of Viet Cong in Sơn Mỹ was inaccurate, however, and the village's population was predominately composed of neutral, unarmed rice-farming families. Reconnaissance aircraft, including Thompson's OH-23 crew, flew over the Sơn Mỹ vicinity but received no enemy fire. At 07:24, without validating intelligence reports, the United States Army shelled Sơn Mỹ, killing many Vietnamese civilians. Following the shelling, Company C (Charlie Company), 1st Battalion, 20th Infantry Regiment of Task Force Barker, led by Captain Ernest Medina, moved into Sơn Mỹ. Upon entering Sơn Mỹ, officers and soldiers of Company C moved through the Song My Village and vicinity, murdering civilians, raping women, and setting fire to huts. 1st Platoon of Company C, commanded by Lieutenant William Calley, forced approximately 70–80 villagers, mostly women and children, into an irrigation ditch and murdered the civilians with knives, bayonets, grenades, and small arms fire. Thompson recounted at an academic conference on Mỹ Lai held at Tulane University in December, 1994: "We kept flying back and forth, reconning in front and in the rear, and it didn't take very long until we started noticing the large number of bodies everywhere. Everywhere we'd look, we'd see bodies. These were infants, two-, three-, four-, five-year-olds, women, very old men, no draft-age people whatsoever." Thompson and his crew, who at first thought the artillery bombardment caused all the civilian deaths on the ground, became aware that Americans were murdering the villagers after a wounded civilian woman they requested medical evacuation for, Nguyễn Thị Tẩu (chín Tẩu), was murdered right in front of them by Captain Medina, the commanding officer of the operation. According to Lawrence Colburn, Immediately after the execution, Thompson discovered the irrigation ditch full of Calley's victims. Thompson then radioed a message to accompanying gunships and Task Force Barker headquarters, "It looks to me like there's an awful lot of unnecessary killing going on down there. Something ain't right about this. There's bodies everywhere. There's a ditch full of bodies that we saw. There's something wrong here." Thompson spotted movement in the irrigation ditch, indicating that there were civilians alive in it. He immediately landed to assist the victims. Lieutenant Calley approached Thompson and the two exchanged an uneasy conversation. Thompson: What's going on here, Lieutenant? Calley: This is my business. Thompson: What is this? Who are