PalArab mortar damages power cable in Gaza

From Ha'aretz:

Palestinian militants fired three Qassam rockets into the western Negev on Wednesday, further unraveling an Israel-Hamas truce in the Gaza Strip.

The rockets struck open areas near a Kibbutz in the Sha'ar Hanegev Regional Council.

Gaza militants earlier in the day fired a volley of mortar shells into Israel, one of which damaged a power cable transferring electricity to the energy-strapped Gaza Strip, according to Army Radio.

Exactly how much of the "power crisis" in Gaza is Israel's fault again?

(Fatah-linked Firas Press reports on electricity failing in Gaza but doesn't mention any mortars.)