Israel-Gaza conflict: Fears grow for hostages held by Hamas as ground invasion looms

The Hamas assault in Israel killed more than 1,300 people, most of them civilians, and they took more than one hundred hostages. Now, the eyes of the world are on Gaza ahead of a looming Israeli ground offensive, where Hamas are believed to be hidden in buildings and the network of vein-like tunnels that run under the Palestinian enclave, a likely place to hold some of the hostages. Jeff Semple reports.