According to eluban.pl:

Tonight, thieves stole a section of the overhead line between Stara Kamienica and Rybnica. As a result, there are disruptions to rail traffic on the Jelenia Góra – Zgorzelec / Görlitz / Świeradów-Zdrój and Wrocław – Wałbrzych – Jelenia Góra – Szklarska Poręba Górna routes.

The Lubań-based outlet adds: – Replacement bus services have been launched for trains on the Jelenia Góra – Stara Kamienica section.

The situation can be monitored on an ongoing basis on the Koleje Dolnośląskie website.