A firefighter was this afternoon undergoing surgery after he and two colleagues fell through a floor while battling a blaze at a Christchurch industrial complex overnight.
Fire Service assistant national commander Dan Coward said the trio fell 3-4m in a two-storey building occupied by Trimble Navigation in Birmingham Drive, in suburban Middleton.
Senior station officer Peter Dellaca and senior firefighters Gary Dillard and Jeff Taylor were injured when the first floor of the larger of Trimble Navigation's two buildings collapsed about 2.15am.
Mr Dellaca and Mr Dillard were released from Christchurch Hospital within four hours, while Mr Taylor suffered injuries to his knees and was undergoing emergency surgery, the New Zealand Fire Service said.
Forty firefighters and 10 fire appliances contained the blaze after several hours.
Mr Coward said the building may have been damaged in the 6.3 magnitude earthquake on February 22 and fire safety officers were investigating whether the trio fell through a hole or the floor collapsed.
"At this stage there are some indications that there has been damage (in the quake) and that was based on visual signs of areas being cordoned off by tape but that could also suggest other things for the building. As part of the investigation process...we will look into that," he told Radio New Zealand.
The cause of the fire had not yet been established.
Trimble Navigation product manager Gary Chisholm told NZPA the building suffered only minor damage in the quake.
"Some ceiling panels fell, I wouldn't call that extensive damage at all," he said.
"We were renewing them and repainting the building."
The building - which housed the company's information technology, land surveying and geographical staff - was "charred, burnt and gutted", Mr Chisholm said.
"We're a fairly resilient business, we're part of a large global organisation so we're familiar with disaster recovery. We don't think it'll have a very big impact on our business.
"We all feel very sorry for what has happened here. A lot of the staff member have maybe lost their homes (in the quake), now they've lost their office.
"They haven't lost their jobs, it's just another shock."
Trimble Navigation's Christchurch managing director, Corrine Haines, said the building suffered only minor damage in the earthquakes and was not unsafe.
Structural engineers had told the company the second story was safe to use, and for workers to carry out repairs. The company opted to put all staff on the ground floor.
Ms Haines said she could not guarantee there would not be any job losses among the 240 staff at the site.
But she told Radio New Zealand Trimble Navigation's US parent company was committed to rebuilding in Christchurch.
Woolston fire station senior station officer Michael Balmer told The Press said the fire was "well involved" when crews first arrived, but was largely under control by 2am.
Mr Balmer said the injured men were taking a hose onto the building's first floor when they fell through.
"Other crews really quickly got them out, it was a real quick operation to get the men out safely."