Five Palestinian smugglers were killed on Sunday and another person was missing after a tunnel collapsed under the Gaza border, Palestinian medics said. According to health official Dr. Moawia Hassanein, the collapse was caused by the heavy rain. Tunnels are regularly used by Palestinians in the Gaza Strip to smuggle in goods that are not available or are in short supply since Israel and Egypt imposed a blockade around the territory in response to the ongoing rocket fire into the western Negev. Palestinians have also used the tunnels as a means of smuggling in weapons. Many tunnels suffered major damage in the aerial bombing campaign of Operation Cast Lead. Egypt has also tried to destroy tunnel entrances on its side of the border. The latest deaths, which occurred late Saturday or early Sunday brought to 13 the number Palestinians killed this year in tunneling accidents.