A woman who was pushing a pram died after she was struck by crane equipment that was hanging off a lorry trailer, a trial was told.
Rebecca Ableman, 30, was with her two-year-old daughter beside the B1050 in Willingham, Cambridgeshire, when she was hit in September 2022.
Kevin Miller, 70, of King's Lynn in Norfolk, denies causing death by dangerous driving.
On the first day of his trial at Peterborough Crown Court, prosecutor William Carter said the equipment was not secured properly and was "plainly potentially lethal".
Jurors were told Mr Miller was transporting scrap metal from King's Lynn docks to two Network Rail depots in Essex and Cambridgeshire on 22 September.
As he passed through Willingham, the loose unsecured crane equipment moved from its position and was hanging over the edge of the trailer and the footpath, the court was told.
Ms Ableman had left a farm shop in Station Road with her daughter Autumn when she was struck by the moving lorry just before 11:15 BST.
She suffered "very serious head and brain injuries", Mr Carter said, and she died three weeks later.
Thomas Butler said he was driving along the road at the time of the collision and told jurors he saw the unsecure equipment.
"[I] thought it looked horrendous and I told my wife it doesn't look all right," he said.
He recalled seeing a woman lying on the road and that cars had come to a halt and there were "people running around all over the place".
The courtroom gallery was packed and there were several members of Ms Ableman's family, including partner Chris Tuczemskyi.
Jurors were told that Mr Miller claimed he did not know there had been an incident until he was arrested at about 13:45 BST.
He said he would have stopped if he had known about the collision and officers heard him say "what's happened mate? I ain't hit no-one", Mr Carter said.
The trial continues.