Travelling on a FCC train on Monday morning, I overheard an announcement on
the train at 08:30 that the tunnel linking Kings Cross Thameslink with the
underground platforms was closed until 10:00 due to severe overcrowding.
Customers were advised to make their way outside by foot to Kings Cross (it
was raining cats and dogs at hte time). Around ten minutes later, I heard
an announcement on the underground that due to overcrowding, the entire
Kings Cross St Pancras station was closed, with no Circle/Hammersmith/Met
trains stopping there until further notice.

Yesterday, there was severe overcrowding at the same station at 17:45,
presumably due to the football at the Emirates Stadium. I managed to make
my way to the Victoria Line, which was becoming dangerously overcrowded -
part closure of the Piccadilly Line didn't help. As I squeezed onto a
northbound Victoria Line train, the tannoy advised "Due to a reported
emergency, can all customers please leave the station immediatley".

Stations like Kings Cross St Pancras can get very overcrowded at peak times
(even more so in Nov when Eurostar at FCC move stations), but is the entire
closure of the station a routine occurrence?