There has been a blaze on the 88th floor of One World Trade Centre in New York.
It is the replacement building for the Twin Towers.
84 firefighters from 26 units were sent to the scene at around 8am local time.
There are no reports of any injuries.
The building is still under construction and unoccupied.
Matthew Coppetto is spokesman for the NY fire department.
“There are reports now that there might not have been a fire” he said.
“It was a possible welding condition”
The massive response by firefighters is standard for calls involving high-rise buildings, Coppetto added and is not a procedure that was implemented in the wake of the September 11th attacks on the World Trade Centre.
1 World Trade Centre is under construction as part of a larger project to rebuild the complex that was destroyed in the attacks.
