A central city Wellington worker has told of hitting a fire alarm when he saw smoke billowing from the building.
Sam, who did not want to use his last name, was among about 2000 workers evacuated from buildings in the Terrace and on Lambton Quay at about 10.25am today.
"We just saw smoke billowing out the side of the building. We couldn't work out where exactly it was from," he said.
"We sort of flapped around a bit, as you do, until we started to say 'it's our building, and even if it's not, we have to go'."
The fire reportedly started in an air conditioning unit in a building which houses TVNZ, the Parole Board and a Les Mills gym.
Sam said his colleague started to break the glass in the alarm "and I finished it for her".
"Basically we were all flapping around ... but I thought that's smoke. We don't know exactly what it is (but) it's time to go."
Staff from the Treasury, the Ministry of Health and the Ministry for Primary Industries were among those evacuated, with the all clear given at about 11.15am.
Something is going very wrong here. pic.twitter.com/Cwkv3nU9N9— Mojo Mathers (@mojomathers) November 4, 2015
One woman who had been evacuated said she believed the fire was started by a welder working on top of the building.
Photos of MPI Fire at bottom of the Terrace. pic.twitter.com/qIkcv8QMTG— Alastair Thompson (@althecat) November 4, 2015
There's a fire on the Terrace, anyone know what's happening? pic.twitter.com/kxoveIvAPP— Narelle (@Narelle_NZ) November 4, 2015
You can take the girl out of journalism ... pic.twitter.com/5TunMgbXk5— Lucy Bennett (@lucybennett99) November 4, 2015