The head of a private school has gone on trial following the death of a nursery pupil who apparently pretended he was Batman and jumped off steps.
Kian Williams, aged three, was a kindergarten pupil
Nicholas Jones, prosecuting, told Mold Crown Court three-year-old Kian Williams had been unsupervised.
Mr Jones said there had been no physical barrier to the steps and only one teacher watching the playtime.
James Porter, 65, of Hillgrove School, Bangor, Gwynedd has denied breaching health and safety laws.
The prosecution said kindergarten pupil Kian, from Bethesda had been carrying a Spiderman toy and pretending he was Batman when he jumped from the fourth step from the bottom of the flight.
He landed face forwards, causing head injuries which led to a coma and pneumonia, from which he died in hospital a month later.
The trial heard that the pupils played on the upper playground, connected to a lower playground by a path and some steps, which should have been out of bounds.
Prosecutor Mr Jones said there was no physical barrier to the steps and only one teacher on duty supervising 59 pupils in both upper and lower playgrounds.
Mr Jones said the teacher on duty positioned herself so she could supervise both playgrounds.
But she had been unable to monitor the steps from where she was.
The depth of the steps was greater than ordinary domestic steps, Mr Jones added.
He said Kian suffered a head injury "sufficient to cause bruising to the right side of the brain and there was a small amount of bleeding to the base of the skull."
Kian, whom Mr Jones described as an "intelligent and lively child," regained consciousness, but there was secondary swelling of the brain and he fell into a coma.
The trial also heard from police, who interviewed a four-year-old girl pupil about what she saw.
Det Con Ian Burns of the North Wales Police family protection unit said she took police to the steps where the fall occurred and showed which step he jumped off.
Unprompted, she pointed to the step and said: "That's where he jumped. He thought he was Batman."
She went on to say that he had a Spiderman toy with him.
In evidence, Det Con Burns said: "She said to us that Kian had gone down the steps. She told him not to go down because he was not allowed but he continued anyway."
Mr Porter, who also owns the school denies that as an employer he failed to ensure as far as was reasonably practicable that pre-school age children were not exposed to the risk to their health by falling on a flight of steps.
The case is continuing.