A coroner's warned parents to make sure young children are always properly supervised when walking near roads.
William Armstrong's comments came at an inquest into the death of 3-year-old Rio Bell from Lowestoft.
He was killed when he was struck by a car in King's Lynn earlier this year.
His mother Kelly said that she and her boyfriend were unable to stop Rio running into the road.
Mr Armstrong said the driver was driving slowly and carefully and was completely blameless.
He said: "I don't want to add to any distress and it pains me to say it, but those who are in charge of young children must make sure they are safe and properly supervised at all times by either holding their hand, putting them in reins or in a buggy."
He recorded a verdict of accidental death.