A look at Israel’s mission to destroy Hamas’ vast tunnel network in Gaza

After passing a series of staging posts, we stopped at the remains of a two-story civilian home, one of the few still standing. The wall of the stairwell had been partially destroyed, forcing Israeli soldiers to duck beneath a twisted iron beam. The only sign of the Palestinian civilians who once lived there was a row of plastic jars on a spice rack, holding sugar and tea bags.

A few feet from the abandoned kitchen, Lt. Col. Ariel Gonen was looking at a small monitor held by one of his soldiers. It showed black-and-white footage from inside a tunnel.

“We’re in big operation to seize as many tunnels as we can, to investigate them and obviously to terminate them,” he told NBC News. “The tunnels are underneath hospitals, everything. We see that they’re under schools, under mosques.”

Gonen said the tunnel on his soldier’s screen was just few yards away, in the backyard of the civilian house. Israeli forces had found it just a few hours before and had dropped a camera down its 15-meter shaft (about 50 feet) to see what was below.

The search for the tunnel had been spurred by an ambush on Friday.

“We got attacked by a few terrorists that came from this tunnel,” said Maj. Maayan Mulla. “They came out, start shooting on us, and they run back. So we searched the area and we found the tunnel.”

Sketching a diagram in the dust, Mulla said the tunnels ran both east to west and north to south. The main prizes for his combat engineering unit were the larger, central tunnels, from which smaller ones shoot off.

The tunnel network is not only a highway for Hamas fighters to travel the Strip without exposing themselves to Israeli air power. They are also a hiding place for the group’s leaders and, Israeli officials say, where the hostages are likely being held.

Mulla said that as his troops explored the tunnels, they had not yet found any sign of the hostages. “They keep them in the center,” he said. “Not up here. That’s for sure that we didn’t find them.”

The fate of the hostages weighs heavily on Israeli troops as they advance. “Everyone in Israel knows someone who was killed or kidnapped,” said one junior soldier sitting on the side of an armored personnel carrier. “Return the hostages,” read the Hebrew graffiti spray-painted onto the side of a partially destroyed chalet.