predictability.
London: From what I've read about the London Blitz (7 September 1940 – 11 May 1941), there is little information on how much time people had to take shelter in London. Based on what my mother has told me - she was in London (near Lord's cricket ground) during part of the Blitz - the time between the siren going off and the first bombs falling was very inconsistent. However, my mother was only 8 or 9 at the time, it was a long time ago, and she wasn't in London for the whole duration of the Blitz so she doesn't know all the details.

Air raids (and thus sirens) could be on and off throughout the night and the warning systems were inefficient in London (though presumably theyor received guilty pleas from four former Trump campaign associates.

Last week, former national security adviser Michael Flynn pleaded guilty to lying to FBI agents. As part of the plea agreement, Flynn has agreed to cooperate fully with the investigation.

A campaign aide, George Papadopoulos, has also pleaded guilty to lying to investigators and is cooperating with Mueller's team.

Two other campaign officials, former campaign chairman Paul Manafort and his associate Richard Gates, also face charges in the investigation. They have both pleaded not guilty.

The House Judiciary Committee is one of several congressional committees conducting separate investigations into Russian interference in the 2016 presidential election.