"...Hamas, which invested between $1 million and $10 million for the construction of each tunnel.
The (Israeli) military estimates it cost Hamas $90 million to build the 32 tunnels that were uncovered.
The average tunnel requires 350 truckloads of construction supplies—enough to build 86 homes, seven mosques, six schools or 19 medical clinics, the Israeli military says.
Most of the cement and other materials used for tunnel construction was smuggled into Gaza through existing underground passageways from Egypt used to bring goods into the territory, said Guy Inbar, a spokesman for the Israeli military's department that oversees humanitarian aid to both Palestinian territories, Gaza and the West Bank.
Some tunnel-building materials also came from aid earmarked for development projects by international aid agencies in Gaza or were purchased on the open market when Israel allowed some imports into Gaza starting in 2010."
http://online.wsj.com/articles/gaza-tunnel-network-fuels-recriminations-in-israel-1407714903
http://online.wsj.com/articles/gaza-tunnel-network-fuels-recriminations-in-israel-1407714903
