I jumped out of this plane only recently. It was a very strange feeling seeing the pictures of it nose down in that field, made me feel quite sick.
I guess it must've had a problem after takeoff since during the training you are told that if there is a problem with the plane and you have enough height then you would all jump out. I guess they didn't have that luxury. I believe even the pilots wore chutes.
But this is still only speculation.
It is an absolute tradegy from a school with an excellent safety record.