Amongst other things, Jubilee was closed from Wembley Park to Stanmore,
the Met seemed to be shutdown altogether; Bakerloo from Wembley Central
ran the last train and left thousands of people milling about wondering
what to do next.

I'm pretty sure that LU will not schedule any maintenance work during
the Olympics.
And Met had "obstruction on the track" at Willesden Green, which was
very unfortunate in timing but was resolved relatively quickly.