Heavy rains and Egyptian interference may be causing Hamas’s entire network of underground tunnels to collapse, a variety of news sources suggest. According to a report in The Jewish Press, two terrorists were killed Tuesday in a tunnel cave-in, one week after another eight lost their lives.

Hamas has built an extensive network of underground tunnels, used to store weapons, smuggle supplies and infiltrate Israel. During Operation Protective Edge in the summer of 2014, Israel destroyed the tunnels known to lead under its borders, one of the main goals of the operation. Hamas officials, such as deputy chief Ismail Haniyeh, have claimed repeatedly that they have been rehabilitating the tunnel network.

On Friday, Haniyeh confirmed such efforts are part of the terror group’s preparations for its next confrontation with Israel. “There are those who think that the calm is a time of rest,” he said, “but this is a continuation of the struggle. Al-Aqsa Martyrs’ Brigades are working and preparing for Palestine. Fighters are digging twice as much as the number of tunnels dug in Vietnam.”

In addition to Israel’s ongoing efforts against such tunnels, Egypt has been pumping salt water into smuggling tunnels reaching into its territory for over a year, Reuters reported. Hamas officials have decried the action, claiming the waters rising to the surface are contaminating the Gazan water supply, destroying farmland and spreading disease.

It was the rainfall, however, which collapsed the northern Gaza tunnel which killed eight terrorists last week. Then this Tuesday, another tunnel collapsed in southern Gaza, killing 35-year-old Fouad Ashor al-Etewi and 23-year-old Ahmad Haidar al-Zahhar from al-Nusirat refugee camp, Ma’an news agency reported. Their identities were provided by Hamas’s military wing, Izz al-Din al-Qassam Brigades.

The tunnels have been a dangerous enterprise from the outset, claiming hundreds of lives. Of particular concern, according to a report by the Institute for Palestine Studies in 2012, is Hamas’s “cavalier approach to child labor and tunnel fatalities,” as “nothing was done to impede the use of children in the tunnels, where, much as in Victorian coal mines, they are prized for their nimble bodies.” The report indicated 160 lives lost of all ages, dating as far back as 2007, while another report, by al-Jazeera in 2014, put the number at 400.