Panorama: London Under Attack

10.15pm, BBC1

If you have problems sleeping on Sunday nights because of non-stop thoughts about the horrors of work on Monday, you probably shouldn't watch this frightening film, which examines the impact of a terror attack on the capital.

Three Tubes explode, a chlorine-gas cloud drifts through Shoreditch, and Panorama's team of experts assesses the response. Police, ambulance and fireservice radios don't work underground, apparently.