A man was held at the scene of a crash on the M6 in Staffordshire in which a mother and three children were injured, one of them an eight-day old baby.
An 11-day-old boy has died following a crash on the M6 in Staffordshire.
Two air ambulances were deployed by the emergency services who continued treating the baby en route to the Birmingham Children's Hospital.
His mother, four-year-old sister and 18-month-old brother were injured in the collision near Cannock yesterday.
The man, from Solihull, was arrested at the scene of the crash on the southbound carriageway near Cannock.
The baby had been airlifted to Birmingham Children's Hospital where he died.
The baby is said to be in a critical condition in hospital.
A 30-year-old man from Solihull has been arrested on suspicion of dangerous driving and released on bail. Police have appealed for witnesses.
Motorway closed
The collision, between a grey Seat Leon and a silver Mercedes C-class, happened on the southbound carriageway near Cannock shortly before 16:30 BST.
Emergency services were called to the scene of the accident, involving a Seat Leon and a Mercedes between junctions 10 and 11 of the M6, shortly before 16:30 BST on Sunday.
The baby and his family were travelling in the Seat. The mother and the two other children were treated in hospital but later discharged.
A West Midlands Ambulance Service spokeswoman said "One child suffered a leg injury and was immobilised and stabilised and the other was described as being in a critical condition".
Two people travelling in the Mercedes were also taken to hospital as a precaution.
She added: "Both were airlifted to Birmingham Children's Hospital for further emergency treatment. Medics travelled in the helicopter to continue vital treatment en route."
The motorway was closed for several hours following the crash.
The mother and children, aged eight days, one and four, were in the Seat when the collision occurred, closing the motorway for several hours.
Two men and a woman in the Mercedes were treated at the scene and two were later taken to Walsall Manor Hospital as a precaution.
The man arrested was held on suspicion of dangerous driving and later bailed, Staffordshire Police said.
