Channel 4 and Channel 5 were taken off the air on Saturday evening and BBC playout re-routed to Salford following a fire alarm at the Red Bee facility in West London.
The Red Bee presentation suite was evacuated around 18.00 GMT, causing BBC World News to drop its half-hour headlines, before going into automation.
BBC One went into ratings winner Strictly Come Dancing with a recorded announcement, leaving viewers unaware of what was happening behind the scenes. BBC One, BBC Two, BBC Four, CBBC and CBeebies are duplicated in both London and Salford, meaning all server material is available in both locations.
Some Channel 4 and More 4 services were restored within 20 minutes, but Channel 4 HD did not return until 22.36. E4, 4Music and Paramount Network were also affected.
In a statement issued on social media, Red Bee confirmed the building had been safely evacuated and no one hurt. “We confirm that all staff at our Broadcast Centre in West London were safely evacuated following activation of the fire suppression systems this evening.
“London Fire Brigade attended the scene, and once they had determined that the building is safe, people were allowed to return to the building. We are continuing to work to restore all services and remedy any issues caused by this incident.”