The Police Ombudsman's Office is investigating the circumstances surrounding the death of a 17-year-old youth in County Antrim.
The teenager fell while on a building site on the Hillsborough Road in Lisburn at about 1930 BST on Tuesday.
He was transferred to the nearby Lagan Valley Hospital, where he died later.
His name has not yet been revealed.
No further details have been released about the teenager's death.