The BBC was forced to switch its playout operations from London to Salford tonight following an incident at the home of Red Bee Media in White City.
Shortly before 6.30pm, everyone working at playout specialists Red Bee was evacuated from the building following reports of a potential fire.
As a result, a whole host of stations went off the air - including Channel 4, Channel 5 and BT Sport - but the BBC's broadcast of BBC One and BBC Two seamlessly switched to a backup operation in Salford.
The only subtle change viewers may have noticed was a generic pre-recorded voiceover ahead of Strictly Come Dancing at 7pm.
The channel's main voiceover artist, Duncan Newmarch, revealed on Twitter: "I've just spent the last two hours stood outside the building. The fire alarm rang out and we could smell smoke in the corridor so had to evacuate- nobody's hurt. BBC1 and BBC2 are currently broadcasting from Salford."
Channel 5 is also thought to be operating on a backup system, having suffered a short blackout during the switch over, although Channel 4 was off air for an extended period of time and is currently broadcasting without audio.