On Thursday evening the IDF took Hamas by surprise, luring them into their tunnel network, known to the IDF as the "Metro", before destroying it, killing an estimated 300-400 Hamas operatives.The “Metro” had been built in the years after the 2014 war in the Gaza Strip, also known as Operation Protective Edge. It was a network of dozens of kilometers of tunnels that crisscrossed Gaza and provided safety for Hamas operatives from Israeli aerial incursions.Besides the Metro tunnel system, the IDF has located and destroyed at least 18 terror tunnels since 2014, according to a 2019 IDF report.