Charlotte Whitby died from multiple injuries yards from her home in Porlock, Somerset, after falling under the rear wheels of the 53-seater coach in February this year.
The hearing in Minehead was told that the automatic mechanism on door of the coach had been disconnected and was opened and closed by an eight-year-old boy.
Cyril Thrush, 65, the driver, who works for Centreville Coaches, Carhampton, was unable to see anything below 4ft 6in (1.37m) in his nearside mirror - where Charlotte would have been standing - and relied on children to operate the door.
In a written statement he said: 'There was a boy on the front seat operating the door. I didn't tell them when to open and close the door, they did it automatically.
'They didn't wait for me to say 'it's safe'.'
Interviews were read of conversations between a school psychiatrist and other children on the bus. The transcripts of an interview with an eight-year-old boy described how he had to leave his seat by the front window to open and close the door. He said: 'I heard someone shouting 'stop' and looked out and saw someone running along close to the bus. I had to stand up to see her.'
Recording a verdict of accidental death, the West Somerset coroner, Michael Rose, accused Somerset County Council of 'gross dereliction of duty'.
He said that the responsibility for the safety of passengers rested with the school authority and should be debated openly at regular times. He said: 'The fact that it has not been debated since December 1989 is an indication of lack of thoroughness on which this committee (the education sub-committee) has gone about its task.
He said: 'If this was a public fare stage bus, this would be breaking the law. It seems to be a fairly serious dereliction of duty and it's important that I make recommendations to make sure repetition of this particular accident is not repeated.' Mr Rose also recommended to the British Standards Institution that toggles on children's clothing should not be on unbreakable cords.Reuse content