Open maps do not preserve Whyburn properties.

We show that a (weakly) Whyburn space $X$ may be mapped continuously via an open map $f$ onto a non (weakly) Whyburn space $Y$ . This fact may happen even between topological groups $X$ and $Y$, $f$ a homomorphism, $X$ Whyburn and $Y$ not even weakly Whyburn.