Researchers at University at Albany did twenty-nine in-depth interviews for gathering first-person accounts of activities, decisions, problems, and solutions of the World Trade Center response and recover process. A generic dynamic theory of collaboration is tested in this interview dataset. The theory is based on Luna-Reyes, et al.ís (2004) model on interagency collaboration. Itís found that during the response and recovery processes participants developed several social accumulations (individual understanding, shared understanding, and relationships). These social accumulations again improved the effectiveness of the processes they were produced. They also increased the effectiveness of other processes in response and recovery effort. These findings are consistent with the generic dynamic theory of collaboration Luna-Reyes, et al. (2004) proposed. A system dynamics model is developed to discuss several different scenarios.