What sort of mileage have you got ?
I am assuming it's an M3W not an older model 2 or 3 speeder.
The ball joint could well be worn but this would not be a sudden fail as you experienced at about 60mph - there have been numerous frame failures of the new M3W and I would be checking that out first very carefully.
There are lots of threads on this in this section, I am not an M3W guy just trying to help, others will be along that are.
