Warning: This article contains information that some people may find distressing.
A woman has died in a fall from the Skywalk viewing attraction on the Sydney Tower in front of horrified witnesses.
A NSW Police spokesman told news.com.au that emergency services were called to Castlereagh St after the death of a woman in the CBD, about 2.40pm yesterday.
"It was a self-harm incident and we can't confirm any other details," the spokesman said.
It's understood the woman threatened self-harm before falling from the building and landing on a canopy below. She has not yet been formally identified, according to police.
A number of witnesses were traumatised, including members of the tour group who were on the attraction with the woman when she became agitated and threatened self harm.
Pictures from the scene shows one woman, apparently in shock, being taken from the viewing deck in a wheelchair. Police are appealing for anyone who saw the tragedy to come forward.
Inspector Robert Winkler described the woman's fall as "very traumatic" and said there had been a large scale response from emergency services.
"We have a deceased person who is being assessed by our crime scene department," Winkler said. "I can't comment on specific details of what has taken place as it's early in the investigation."
A NSW Ambulance spokesman told news.com.au that paramedics had responded to reports of a woman threatening self-harm at Centrepoint Tower today.
"Two paramedic crews responded and were on scene by 2.45pm," the spokesman said.
The woman was dead on arrival and paramedics left soon after, according to the spokesman.
He said there were also reports of witnesses in shock.
"Paramedics are providing support to police as required," he said.
Police will prepare a report for the coroner.
Sections of Castlereagh and Market Sts, which surround the building, were closed.
News.com.au has contacted Sydney Tower for comment.
The building, also known as Centrepoint Tower, offers the external Skywalk experience as part of a viewing attraction at the top of the building. The Skywalk was constructed in 2005 at a cost of almost $4 million.
"Step out into the open air for a breathtaking 45-minute tour around the outside of Sydney Tower with one of our experienced guides," the site reads. "You can enjoy the views from the internal Observation Deck before and after your Skywalk tour."
The 309m tall tower is "ranked as one of the safest buildings in the world", according to the Sydney Tower Eye's website.
"The striking design has made the tower capable of withstanding earthquakes and extreme wind conditions," it reads.
"The breathtaking 360-degree, sky-high views stretch for more than 80km in any direction."
It has been closed until further notice.
Where to get help:
• In an emergency: call 111
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youthline: 0800 376 633, or text 234 (available 24/7) or email@example.com or live chat (between 7pm and 11pm) http://livechat.youthline.co.nz/mibew/chat?locale=en&style=youthline
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• Depression helpline: 0800 111 757 (available 24/7)