The Jerusalem Post reports:
IDF troops discovered an underground tunnel earlier this week that had been dug by terror operatives on the outskirts of the Shajaiyeh neighborhood in Gaza City. The opening of the 13-meter-deep, 150-meter-long tunnel was found inside a building at least one kilometer away from the Gaza security fence. It was believed that the target of the attack was the nearby Karni Crossing. It was as yet unclear whether the tunnel - similar to the one used by Palestinians in June's attack on the IDF outpost at Kerem Shalom in which Cpl. Gilad Shalit was abducted - was intended as a means of infiltrating Israeli territory, or whether it was meant to be rigged with explosives.
Here's the tunnel:
So Hezbollah lobs missiles over Israel's border, and Palestinian terrorists tunnel under it.