Euston to Camden (Charing Cross Branch) was very quiet a 08:50. My carriage
had probably 6 passengers in total.

TFL site says
################################################## ###########
When the Northern line service resumes to all stations, it is planned to
operate two separate branches over the whole line until further notice:

- Edgware to Morden via Bank ONLY; and,
- High Barnet and Mill Hill East to Morden via Charing Cross ONLY.
################################################## ###########

Is this because the points are still damaged, or because they don't know why
the train derailed ?