A young boy fell through the roof of a swimming pool in St Helens and is in hospital in a serious condition.
The emergency services were called to the dramatic incident at Parr Swimming Baths at around 6.20pm on Sunday.
Police attended after officers received reports that three youths were seen on the roof of the building and one, who is 12 years old, fell through.
His injuries will be assessed in hospital.
Enquiries have now begun to establish the exact circumstances.
Anyone who witnessed the incident, or has any information, is asked to contact Merseyside Police by ringing 101, quoting reference number 822 for the date of Sunday June 23, or ring independent charity Crimestoppers on 0800 555 111..