National Rail enquiries site says 'Delays through Gatwick Airport expected until 13:30'. Doesn't look too major. Can only see two cancellations out of more than a dozen trains into Brighton (via East Croydon) between now and kick-off.
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Incidentally, if it's all going to be sorted by 1330, why is the 1336 cancelled already?
That'll take a good hour to remove from the line, 6 engineers to sort it out?