Dozens of New York firefighters rushed to the World Trade Center skyscraper early Wednesday after a member of the public mistook welding for a fire.
Initial reports from the New York Fire Department suggested a minor blaze on the 88th floor of One World Trade Center, the centerpiece in the project to replace the Twin Towers destroyed in the September 11, 2001 terrorist attacks.
A spokesman told AFP the fire was brought under control in less than an hour.
Subsequently the department said that 84 firefighters had been dispatched to the still unfinished tower after a member of the public reported seeing a fire.
However, the incident took place in an area where construction workers have been welding steel and the incident appeared to have been no more than "a flash," the spokesman said.
However this was not a false alarm. "There was an incident at the scene. Calling us on 911 was necessary," the department spokesman said.
Nearly 3,000 people died during the September 11, 2001 attacks on the Twin Towers and security at the new site is always high.