A blaze that broke out when three vehicles crashed under a railway bridge forced the closure of the line causing major disruption to train services.
Four people, including two young children, have been taken to hospital after emergency crews were called to the bridge, on Manor Road, Bilston, at about 11:15 BST.
One of the vehicles involved had earlier been pursued after failing to stop for officers, West Midlands Police said.
The crash disrupted the route between Birmingham New Street and Wolverhampton and is also affecting services between Shrewsbury and Stoke-on-Trent, operators said.
A woman, along with the children, is being assessed in hospital, but none of them are thought to have life-threatening injuries, West Midlands Police said.
Vehicles fully ablaze
A man, the fourth person injured, was also taken to hospital, after being arrested on suspicion of dangerous driving and failing to stop.
He was detained after a Volkswagen Golf, BMW and a van were all found fully engulfed by flames, when crews arrived, West Midlands Fire Service said.
Disruption to services, also affecting Avanti West Coast and Transport for Wales, was expected to last until about 17:00, National Rail said.
Many trains were left stranded as a result of the fire and services between Shrewsbury and Wolverhampton would be covered by rail replacement services, West Midlands Railway said.
Rail tickets can also be used with Metro tram and National Express coach services, it added.
London Northwestern Railway said the fire had led to a lack of trains to cover the Potteries – Crewe to Stafford via Stoke-on-Trent – and replacement services would be also put in place.
Signal failure
Passengers using Cross Country services have also been warned about the disruption caused by the blaze.
The occupants of the BMW had to be helped from their vehicle, following the crash.
Police will interview the arrested man in due course, a spokesperson said.
The force’s professional standards department has been informed, which is standard procedure in such circumstances, the spokesperson added.
In a separate incident, a fault with the signalling system between Birmingham New Street and Walsall has blocked all lines and caused trains between Birmingham and Walsall and Rugeley Trent Valley to be cancelled, National Rail added.
The incident was first reported at about 23:00 on Friday and disruption is expected until 19:00.