  The prism over a graph $G$ is the cartesian product $G \Box K_2$. It is known
that the property of having a Hamiltonian prism (prism-Hamiltonicity) is
stronger than that of having a $2$-walk (spanning closed walk using every
vertex at most twice) and weaker than that of having a Hamilton path. For a
graph $G$, it is known that $\alpha(G) \leq 2 \kappa(G)$, where $\alpha(G)$ is
the independence number and $\kappa(G)$ is the connectivity, imples existence
of a $2$-walk in $G$, and the bound is sharp. West asked for a bound on $\alpha
(G)$ in terms of $\kappa (G)$ guaranteeing prism-Hamiltonicity. In this paper
we answer this question and prove that $\alpha(G) \leq 2 \kappa(G)$ implies the
stronger condition, prism-Hamiltonicity of $G$.
