Unlike the previous 2 Gaza operations, the IDF is now engaged in house-to-house combat in a densely populated neighborhood of Gaza. Shejaiya, the eastern neighborhood of Gaza City, is only two kilometers from the Israeli border.
Many houses in Shejaiya hide entrances to tunnels, most of which lead several kilometers under the border into Israel. The tunnels are a hiding place for terrorists and storage for rockets and other weapons. Hamas started to use the tunnels for murder-kidnapping attacks on communities and soldiers near the border.
Israel was surprised by the number, size and sophistication of the underground network. Estimated to cost several million dollars each, the solid concrete tunnels have lighting, ventilation and electricity. The number of cross-border tunnels is currently estimated at 60, but could be higher. Israel considers their destruction critical to the safety of Israel's citizens.
Also a first, Israel destroyed a hospital - the al-Wafa rehab hospital was also a Hamas command centre and rocket launch site. Israel gave advance warning to allow evacuation of patients.