Documentary exploring the recordings of telephone calls made by people who were trapped in the World Trade Centre during the terrorist attacks in September, 2001. The programme examines previously unheard audio files, home films and testimonies from the victims' relatives, who reveal how the messages have helped them cope with the deaths of their loved ones. Featuring a call by Jim Gartenberg, who stayed on the telephone with his pregnant wife until the towers collapsed, and a businessman who left a message for his mother