"It's pretty messed up. He said the boy was playing in the lift, because they are massive houses and they have lifts, and he got his head crushed.
"He was pretty spooked. He tried to give him CPR but it didn't do anything."
Pacific Cliffs Drive is a cliff top street that borders the exclusive Gulf Harbour Country Club and golf club and overlooks the picturesque harbour.
There were a lot of new houses being built and some houses being renovated on the street, said Mr Denz.
"Kids wouldn't be on a building site. He was just playing around, but I don't understand because all the lifts in the houses are pretty safe so we don't know how he would have done it."
A neighbour, who did not wish to be named, said the child was the grandson of the home's owner.
She said she had seen one fire truck, four police cars and two ambulances attend the scene and police had asked for neighbours to stay away.
She described the home's owner as a "quiet man" who kept to himself.
The neighbour's husband, who works at the marina, said he had seen emergency services heading to the home.
"I just saw the vehicles arriving and I called my wife to see why was happening."
He said the boy had been playing hide and seek when he was injured.
"It is tragic, what else can you say. He was playing hide and seek or something. Must have been horrendous because his siblings would have been there."
Workers nearby also heard "a lot" of sirens in the area close to 1pm.
"I was thinking what on earth has happened because they sounded so close," said one worker, who wished not to be named.
Auckland Westpac Rescue Helicopter was also called to the address shortly before 1pm, but were stood down.
In a statement tonight, police said the boy died "following a fall at his home".
Police were called to the residential property at 12.58pm.
"Despite extensive efforts by family and emergency services, sadly the boy was unable to be revived and died at the scene," the statement said.
"Police believe this is a tragic accident and as such, the death will be referred to the coroner."
The exact events that led to the fall will form part of the information that Police will provide to the Coroner.
"We are all immensely saddened by this young boy's death and our thoughts are with his family tonight."
Rodney Police Area Commander Mark Fergus said the boy "was playing just like any other 11-year-old boy does and this is very upsetting for everyone involved".
Mr Fergus said the family had requested privacy and he also issued a remind to people commenting about the tragedy on social media.
"We ask that the media respect the family's privacy and that social media users bear in mind that speculating around the circumstances of such a tragic accident can be very hurtful to a victim's family."
The Manly Fire Station in Whangaparaoa was called to the incident, but a spokesman would not comment on the service's role there.
Contrary to early reports, the incident did not take place at a construction site.
