Concrete falls from Thameslink tunnel roof, halting all trains through central London until at least 3pm

Concrete fell from the ceiling of a railway tunnel in central London on Sunday morning, bringing Thameslink services through the city centre to a halt. The damage is in the Snow Hill Tunnel, between Farringdon and London St Pancras International. Debris fell onto the track and damaged the overhead power wires. Thameslink said both tracks on the core section between St Pancras International and Blackfriars were closed and expected to remain so until at least 3pm London time, while Network Rail engineers inspect the tunnel and carry out urgent repairs.

Cause unknown as services divert or stop

It is far too early to say what caused the concrete to fall, and it is not yet confirmed whether the location aligns with any construction sites on the surface. Cambridge trains that normally run through to Brighton are starting and finishing at King's Cross, the Bedford service has been cut to two trains an hour, and services between Luton and St Albans and on the Sutton and Wimbledon loop have been suspended. Thameslink is advising passengers to allow at least an extra hour for their journeys — 90 minutes if heading to Gatwick or Luton airports — and tickets are being accepted on the Underground, buses and alternative rail services.

(File photo: a Thameslink train at St Pancras International station.)