9/11 - Did You Know: BBC Reports on Building 7

A video from the archives shows the BBC reporting on the collapse of WTC Building 7 over twenty minutes before it fell at 5:20pm on the afternoon of 9/11. The incredible footage shows BBC reporter Jane Standley talking about the collapse of the Salomon Brothers Building while it remains standing in the live shot behind her head. How did the BBC know that it was going to collapse? And why did they report the collapse when it is clearly standing in the background?