The Christchurch offices of many national New Zealand firms have been severely damaged by Tuesday's earthquake.
Duncan Cotterill, whose Christchurch office was situated in the badly damaged Clarendon Tower, had around 35 members of its corporate team trapped on Level 9 after the stairs had caved in.
All Duncan Cotterill staff eventually made it to safety.
The firm's chief executive Janice Fredric said that staff were working on IT matters and finding temporary accommodation, as it will be "some time" before they can even gain access to the building.
The Christchurch office of Simpson Grierson was also badly damaged.
Other law firms with offices in the region affected include Buddle Findlay, Cavell Leitch and Chapman Tripp. These three firms have released statements acknowledging that staff are safe.
The Law Society of New Zealand reported that its Christchurch office was in a state of "disarray".
The death toll from the earthquake officially stands at 76, but is expected to rise with many people still unaccounted for.
The Christchurch CBD is effectively closed, with a curfew in that area introduced overnight.