A three-year-old girl has died after she became entangled in a piece of equipment in a play area.
The girl suffered serious injuries in the play area at York College on Monday and was taken to York District Hospital, where she was pronounced dead.
North Yorkshire Police said they did not believe there were any suspicious circumstances.
The scene has been cordoned off while officers investigate the incident and Ofsted and the Health and Safety Executive have been informed, a spokeswoman said.
The force spokeswoman said: "At this stage, police do not believe there are any suspicious circumstances and it appears that the girl has become entangled in a piece of play equipment.
"The police are carrying out an investigation into the incident to establish exactly what happened and would like anyone who was in the area at the time to contact them."
No-one was available for comment at York College.
The police spokeswoman said the accident happened in an outdoor play area at York College Nursery. She said the nursery would be closed on Tuesday.
The nursery website says the facility provides full daycare provision for children aged between six weeks and five years.
It opened in 2007 and has three play rooms, each with access to a fully enclosed outdoor area.
An Ofsted inspection carried out in September 2009 said the overall quality of provision at the nursery was good.
The inspector said in the report: "Risk assessments, which cover the indoor and outdoor environment of the nursery, reduce the possibility of accidents. Children are taught to be safety conscious and they show a sound understanding of how to keep themselves safe."
The outdoor facilities at the nursery are described as "superb".
A spokesman from the City of York Council offered sympathies to those who knew the three-year-old girl.
He said: "All relevant agencies are aware and will be working together over the next few days.
"This evening our thoughts are with the family of the child and staff at the nursery."