Cut the second circle factor at . This divides the torus into two annuli whose boundary circles are exactly the two collapsed circles. Collapsing each annulus's two boundaries separately produces a two-sphere; the two spheres then share their two poles. In particular, the two collapsed circles give two distinct vertices, not a single common collapsed point.
For an explicit cellular homology calculation, each suspended circle contributes one edge from the first vertex to the second and one two-cell attached with zero cellular boundary. Thus , , , with no higher cells. Both edges have boundary , so has rank one and kernel generated by the difference of the edges. Each two-cell's attaching loop traverses its edge in opposite directions, so . Consequently the homology of a torus with two parallel circles collapsed is
Collapsing either connecting edge as a maximal tree also exhibits the homotopy type .