I will discuss the metric behavior of the Kahler-Ricci flow on $\mathbb{P}(\mathcal{O}_{\mathbb{P}^n} \oplus \mathcal{O}_{\mathbb{P}^n}(-1)^{\oplus (m+1)})$, assuming that the initial metric satisfies the symmetry defined by Calabi. I will describe the Gromov-Hausdorff limit of the flow as time approaches the singular time and how the Kahler-Ricci flow can be continued. This is a joint work with Jian Song.