Let $B$ be a topological space. A universal covering of $B$ is defined to be a simply connected covering space. Suppose $B$ has a universal covering. Is such a covering unique (up to a homeomorphism)?
When $B$ is locally path-connected, the lifting criterion easily implies the uniqueness of a universal covering. This can also be shown 'by hand' using the homotopy lifting property, or can be shown by playing with the fibered product of two universal coverings. But now $B$ is not assumed to be locally path-connected, and none of these work.
Question: Is the universal covering unique?