Making spaces wild (simply-connected case)

We attach copies of the circle to points of a subset D of a separable metric space X and construct an earring space E(X, D). We show that the fundamental group of E(X, D) is isomorphic to a subgroup of the Hawaiian earring group, if the space X is simply-connected and locally simply-connected. In addition if the space X is locally path-connected, the space X can be recovered from the fundamental group of E(X, D). (C) 2020 Elsevier B.V. All rights reserved.