My question arose when I was working on a research problem. It is as following:
Let $M$ be a homology manifold whose homology groups are the same as a sphere. Assume further that the double suspension of $M$ is homeomorphic to a sphere. Is $M$ homeomorphic to the suspension of a homology sphere?
Edition: Is $M$ homeomorphic to either suspension of a homology sphere or homeomorphic to a homology sphere.