Rail replacement buses are running between Pitsea and Grays - with journey times extended by up to an hour.
The disruption is expected to last until lunchtime.
More top news
Britney Spears sung hits from all nine of her albums during her highly-anticipated appearance at the Apple Music Festival in London.
The Met Office says temperatures are likely to climb above 20 celsius.
In a sketch for 'The Late Late Show', James Corden temporarily took charge with some unusual coaching techniques.