Eleven-year-old Francis Rowntree was shot by a soldier in west Belfast in 1972.
Henry Donaghy, who was with Francis on the day, has been giving evidence to the inquest.
Mr Donaghy, who was 14 at the time, told the court there were no cars on fire or rioting in the area.
He said that while he could hear disturbances nearby, the trouble had moved along the road.
Explaining that they were making their way though the area when they came across an army vehicle, Mr Donaghy said:   "Wee Francie was more curious than the rest of us.
"He started to walk towards the Saracen.  He wasn't carrying anything."
He told the inquest that Francis was ahead of the rest of the group and just eight to 10 yards from the vehicle when he heard a loud bang.
He said Francis appeared to be "lifted off his feet and jerked backwards".
He said he knew something was "desperately wrong".
"It scared us, the colour on his face."
Mr Donaghy said the observation flap at the rear of the Saracen was "completely open" and all he could see after the bullet had been fired was "smoke and powder debris" coming from an area around the Army vehicle.
Francis Rowntree, known as Frank by his family, died in the Royal Victoria Hospital two days after being hit - on 22 April, 1972.
An inquest into the death of a boy who was hit by a rubber bullet has been told he was only a few yards from an Army vehicle when he was shot.