A video uploaded by the Dunedin City Council shows the moment a power supply shorted out and exploded in rainbow colours in its central city headquarters this morning.
Hundreds of staff were forced out of the building about 9.15am and firefighters called, after initial reports of a loud bang inside the council's third floor computer server room.
A council spokesman said an uninterruptible power supply shorted out which triggered the non-toxic gas system to cool and reduce oxygen in the room.
No information had been lost as the council's production servers were hosted off site and staff began moving back into the building about 10am.
