Video footage has emerged, showing a sea of faces as hundreds of Sheffield school children are evacuated from City Hall.
The kids were ushered from the building on Barker's Pool when a fire alarm sounded in the middle of a performance of the Halle Orchestra.
Firefighters from Sheffield Central Fire Station were called to the scene at 11.27am.
A South Yorkshire Fire and Rescue spokesperson said it was a false alarm.
A Sheffield City Hall spokesperson said the children were evacuated 'quickly and safely'.
The concert, he said, was soon under way again.
The Manchester-based orchestra was due to play again at 1.30pm.