Two boys aged six and seven years old have been knocked down and killed as they tried to push their scooters across a busy three-lane motorway.
Police shut the motorway to carry out inquiries
The pair were making their way across the westbound carriageway of the M56 at Preston Brook, near Runcorn, when they were hit.
Cheshire Police said at least three cars were involved and the boys were pronounced dead at the scene.
The incident took place just before 1930 BST on Wednesday.
The boys, who have not yet been formally identified, are thought to be from the nearby Murdishaw area of Runcorn.
It is understood they had been reported missing a little while earlier, and police were said to be looking for them at the time of the accident.
Insp Russell Barnes from Cheshire Police said: "It is an absolute tragedy for everyone involved, both the family of these two boys and the people who witnessed it.
"We had numerous 999 calls from drivers on the motorway to say that they had seen these two boys with their scooters on the hard shoulder.
"The police and highways agency deployed patrols but by the time they got there the collision had just happened."
Police said as they arrived people were swerving across the motorway to avoid the scene.
Insp Barnes said: "The boys were hit by three cars. The drivers wouldn't have been able to see them until it was too late.
"It is a rural part of the county there, it's unlit and there are no CCTV cameras.
"I just feel for everybody involved."
Residents in the close where the boys lived were said to be in "deep shock" after a woman who lives nearby broke the news.
A neighbour said: "It is absolutely terrible news.
"We heard they had gone missing and the families were out looking for them
yesterday evening, and then we heard that there had been this terrible crash on
The Chester-bound carriageway, a busy route for those commuting between Manchester and Cheshire, was closed temporarily by police while investigations were carried out.