A BUS driver described the "mayhem" in his vehicle before a teenager fell out and was crushed under the wheels.
Peter Marsh, 57, of Rock Cottages, New Mill, denies dangerous driving.
He told a jury at Bradford Crown Court yesterday he was "eternally sorry" for the incident on April 26, 2002, in which Marc Jackson received horrific injuries after falling from the open door.
The 15-year-old Colne Valley High School pupil was run over by the school bus in the centre of Milnsbridge.
Marsh told the jury how he drove for virtually one-and-a-half miles, along Cowlersley Lane and Morley Lane, with the front doors open.
He said youngsters had tried to open the doors on the same service just a few days earlier.
On that occasion, he was able to keep them shut - even when Marc Jackson had reached for the driver's door control.
"Marc Jackson jumped across and laid on the steering wheel, trying to get my hand off the button," said Marsh. "I fended him off."
But on Friday, April 26, three boys opened the folding doors and blocked them. A safety mechanism ensured they did not shut if obstructed.
"Once they had them open they just stood with their backs to them to block them," said Marsh.
He said it was mayhem on the bus.
He told the court he ordered the boys "to get inside and not be so daft". But the gang refused to listen.
Marsh said he did not see the boys hanging from the bus or dangling their legs and arms from the open doorway, as witnessed by other drivers. His view of their antics was blocked by more pupils standing alongside his cab.
He said he wanted to regain some control. "I was hoping upon hope I would met a police car coming up the hill so I could flag him down," he added.
As the vehicle approached Milnsbridge and turned left, Marc Jackson fell.
"There was this almighty scream from inside the bus of `Stop, stop, stop'," Marsh told the court.
He stopped the bus and at first thought the bus had run over the teenager's leg.
"I could see Marc laid in the road. I think he had his head laid on the kerbside, with his body out into the middle of the road."
Prosecutor Jonathan Gibson asked him: "Do you believe that moving with the doors open was a dangerous thing to do in those circumstances?"
"Yes," replied Marsh.
"There was an obvious risk of serious injury to someone wasn't there?" continued Mr Gibson.
"Yes," said Marsh.
Mr Gibson said the court had to look at how a prudent driver would have acted in the same circumstances.
Marsh's main duties with the Teamdeck bus company were as a mechanic, but he occasionally drove the vehicles.
The court heard he still worked for Teamdeck and had driven buses on other routes.
The case was adjourned until Monday.