Neighbours have left flowers outside a house where a child was involved in a medical emergency and later died in hospital.
Police forensic teams combed the Larne property throughout Thursday, while officers remained at the scene on Friday.
The child, believed to be a girl, was taken from the property in the Antiville area of the town to Belfast's Royal Hospital for Sick Children, where she passed away.
A post-mortem was due to take place on Friday as the PSNI urged "people to refrain from speculation in relation to this death".
Locals described how police and other emergency services, including an air ambulance, descended on the area around the property on Loran Avenue shortly after 1pm.
The emergency services were responding to a report of a "medical emergency".
DUP Councillor Andrew Clarke said the child's death was "a trauma" for the community. Some responded by bringing flowers and laying them against the front wall of the property on Loran Avenue.
"This is a quiet area, not a lot happens, which is a good thing, and then something like this out of the blue is pretty horrific," Mr Clarke told PA News.
"Any death, any sudden death, is a shock, but when you have a child, someone who is full of life and happiness and is suddenly taken away, it really is quite a trauma I think for the community, and also for the family, and our hearts go out to them."
Mr Clarke said the incident was "devastating" for the town.
"Ambulances came, the air ambulance came, police were tasked, there was quite a commotion, traffic being interrupted and so on," he said.
"And then news began to filter out that a young girl had sadly lost her life, that's been confirmed by the police.
"The impact has been pretty, pretty devastating. Here and all round the town, there's a sense of disbelief, a sense of shock that something like that would happen in this area."
A PSNI spokesperson asked people not to speculate on the cause of death.
The spokesperson said: "Officers received a report yesterday afternoon, Thursday November 9, of a medical emergency involving a child, at a property in the Loran Avenue area of the town.
"A child was taken to hospital but sadly passed away. A post mortem will now be carried out today to determine the cause of death and inquiries remain ongoing.
"Until a post mortem is completed, we will not know the cause of death and would, therefore, urge people to refrain from speculation in relation to this death."
The Northern Ireland Ambulance Service said it attended a call just after 1pm on Thursday.
"The Northern Ireland Ambulance Service received a 999 call at 1.07pm on Thursday following reports of an incident in the Antiville area of Larne,” a spokesperson said.
"NIAS dispatched a rapid response paramedic and two emergency crews to the incident.
“The charity Air Ambulance, with HEMS crew on board was also asked to attend."
"Following assessment and initial treatment at the scene, one patient was taken by ambulance to Royal Belfast Hospital for Sick Children.”
