East Midlands Railway say that there line from Luton to London St Pancras is closed.
Update 2 pm line reopens
EMR said at 1:22 pm on Tuesday 30 February:
‘Line closed between Luton Airport Parkway and London St Pancras this is because of a road vehicle has colliding with a bridge.’
‘A road Vehicle has collided with a bridge north of Harpendon. This is between Luton Airport Parkway and London St Pancras and is disrupting our trains on the London St Pancras/Nottingham/ Sheffield route and the connect services.
‘Network rail are on the way to the site to investigate the problem. They are expected to arrive in 30 minutes.
‘Trains running through the area in the towards the north (Sheffield/Nottingham/Leicester) cannot run.
‘Trains running through the area towards London St Pancras can run but this will be at a reduced speed as we have limited use of the track. Please be prepared for delays.
‘At present we are expecting the problem to be fixed in the next 2 hours. As soon as the problem is fixed our priority will be to get trains running to their advertised times again. We expect our advertised timetable to resume on the affected routes by 15:00.’