The line bundle mean curvature flow is a complex analogue of the mean curvature flow forLagrangian graphs, with fixed points solving the deformed Hermitian-Yang-Mills equation. In this
paper we construct two distinct examples of singularities along the flow. First, we find a finite
time singularity, ruling out long time existence of the flow in general. Next we show long time
existence of the flow with a Calabi symmetry assumption on the blowup of P^n, if one assumes
supercritical phase. Using this, we find an example where a singularity occurs at infinite time along
the destabilizing subvariety in the semi-stable case.