A thread about this has been made in the Out of Focus forums.
All those involed are not in a life threatening condition and are getting better all the time. Two marshalls and a photographer were hit after a rally car left the track and up a grass bank - This was by the flying finish of SS1, the first stage of the day.
The organizers adjusted the track while investigations took place, and the event continued after a drivig briefing.
I have personally shot at this event last year, and it is very open. I assume it was a very high speed crash (flying finish, so maybe lack of brakes?) meaning those three injured could not get out of the way quick enough.