There are severe delays on the rail network this morning after a fire alarm at Three Bridges station meant he signalling centre had to be evacuated.
Train services across the whole Southern network are being being disrupted and delays of up to 45 minutes can be expected.
Emergency services investigated the problem and staff are now back in the building.
A spokesman for Southern said services will be subject to short notice alterations and cancellations this morning.
Journey times on all routes between Brighton / Horsham and East Croydon may be extended by up to 90 minutes.
Log on to www.southernrailway.com for more details