The head of the Law Society said the organisation has been left “extremely upset” after a fire broke out at its historic offices in central London.
Chief executive Paul Tennant thanked the London Fire Brigade (LFB) for its efforts in battling the blaze that hit the roof of the building on Chancery Lane on Saturday night.
About 28 people left the building before emergency services arrived, while a further 11 had to be evacuated from nearby flats as a precaution.
The LFB said about 150 firefighters and 25 engines were sent to tackle the blaze at the six-storey office building at 10.40pm.
A spokesman for the Law Society said a junior lawyers division dinner had been taking place, but all were evacuated safely from the building.
Mr Tennant said: “First of all I wanted to express my gratitude to the fire service and my relief that nobody has been hurt.
“I also want to express my sympathy to the residents in the Chancery Lane area whom I understand may have had to evacuate their homes.
“It is too early to comment on the cause of the fire or the extent of the damage but clearly we are extremely upset that this has happened to this wonderful and historic building.
“When the fire alarm sounded on Saturday night an event had been taking place.
“An evacuation ensued and I’d like to praise our on-site staff and others for their calm response.”
The LFB said the fire was brought under control shortly before 10am on Sunday.
It said the building’s roof and a staircase from the third to the fifth floor were destroyed by the fire, while half of the third and fourth floor were also damaged.
Assistant commissioner Dom Ellis, who was at the scene, said: “This was a very complex fire due to the age and layout of the building.
“Firefighters worked throughout the night in very challenging and arduous conditions to prevent the fire from spreading to key areas of the historic building, while also trying to prevent water damage.
“They will remain on scene throughout the day damping down and cutting away.
“There will also be ongoing salvage work to minimise damage to the building.”
The cause of the fire is under investigation.