A toddler died on her first day at nursery school when she became entangled in the 'loop' of a rope at the top of the slide after being left to play alone.
A court was told that three-year-old Lydia Bishop died after the rope loop tightened around her neck and choked her as she slid down.
Despite the fact no children were allowed to be in the play area alone, it was 20 minutes before Lydia was found by a member of staff.
She was 'blue' and not breathing and efforts to revive her failed.
Leeds Crown Court was told that Lydia died just five hours after being dropped off by her parents at the nursery at York College.
Prosecutor Robert Smith, QC, told the jury there was a 'tick-box mentality' at the nursery, with staff focusing on 'excellent' paperwork rather than ensuring safety rules were adhered to.
He added: "Compliance with health and safety law was done on paper but not in practice."
It was alleged that Sophee Redhead, 25, was one of the nursery staff supervising Lydia and saw her walk in the direction of the slide, but did nothing to stop or supervise her.
She denies manslaughter by gross negligence and an alternative health and safety charge of failing to take 'reasonable care' of the little girl.
York College, which owns the nursery, is also on trial and has denied failing to ensure people not in its employment are not exposed to a risk to their health and safety.
On the day of the tragedy in September 2012, staff had placed a makeshift barrier across the path leading to the slide in a 'futile attempt' to stop children going there unsupervised.
The nursery regularly used ropes for play, but risk assessments had identified the potential danger of strangulation from rope attached to the slide.
Strict rules – posted on the nursery walls – stated no children should play on the slide without adult supervision and the rope should be put away when staff were not there.
The tragedy happened when most of the children were enjoying a snack.
A doctor said Lydia could have recovered if she had been found after a few minutes.
The trial continues.