The SkyCity International Convention Centre fire is expected to burn overnight as firefighters fear the building's roof may collapse.
Footage taken from a nearby apartment building around 8:30pm shows the fire is still burning strong more than seven hours after it began.
A Fire and Emergency NZ spokesperson told 1 NEWS the current plan is to "sacrifice part of the roof" where the fire is burning.
They say the fire is under control and the firefighter taken to hospital in a serious condition earlier in the day has now been released after suffering a medical event.
Earlier, a Civil Defence emergency alert was sent out to cellphones warning Auckland CBD residents about smoke inhalation from the convention centre fire.
Earlier today in a statement from SkyCity they said: "Due to the smoke from the NZICC fire, we have made the decision to undertake a controlled evacuation of the full SkyCity Auckland precinct.
"This includes the Sky Tower, Casino, all SkyCity Hotels and restaurants and corporate offices. Police are on precinct and are available to assist with evacuations if or where necessary."
In a later statement at 9.45pm SkyCity says: "We hope to be open by lunch time tomorrow (Wednesday) but will confirm in the morning. That includes the Sky Tower, Casino, Convention Centre, hotels and restaurants.
"SkyCity has rehoused all of our hotel guests that were on site with a few still to check in."
They also say they hope to have the SkyCity carpark open tomorrow (Wednesday).
Road closures in the immediate vicinity of the fire are still in effect and may hamper early morning rush hour traffic.