There is evidence that the Central Plains/Initial Coalescent villagers built well-planned defensive works for their village. They were replacing an earlier dry moat fortification with a new fortification ditch around the expanded village when an attack occurred that resulted in the massacre. The attacking group killed all the villagers. Archaeologists from the University of South Dakota, directed by project director Larry J. Zimmerman, field director Thomas Emerson, and osteologist P. Willey found the remains of at least 486 people killed during the attack. Most of these remains showed signs of ritual mutilation, particularly scalping. Other examples were tongues being removed, teeth broken, beheading, hands and feet being cut off, and other forms of dismemberment. In addition to the severity of the attack, most of the people showed signs of malnutrition and many had evidence of being wounded in other attacks. This evidence has suggested to scholars that lives of people of the Initial Coalescent culture were under more stress than was thought; they have theorized that the people were attacked by another group or several groups of the Initial Coalescent culture in the area in competition for arable land and resources.