Consider  the  following  causal  explanation:   The  ball  went through the goal because the defender didn’t block it.  There are at least two problems with citing omissions as causal ex- planations.   First,  how  do  we  choose  the  relevant  candidate omission (e.g. why the defender and not the goalkeeper). Sec- ond, how do we determine what would have happened in the relevant  counterfactual  situation  (i.e.   maybe  the  shot  would still have gone through the goal even if it had been blocked). In this paper, we extend the counterfactual simulation model (CSM) of causal judgment (Gerstenberg, Goodman, Lagnado, & Tenenbaum, 2014) to handle the second problem. In two ex- periments, we show how people’s causal model of the situation affects their causal judgments via influencing what counterfac- tuals  they  consider.   Omissions  are  considered  causes  to  the extent that the outcome in the relevant counterfactual situation would have been different from what it actually was.