Remember that the ATR is a
high-wing aircraft. The fuel is in the wings and thus the
last thing that will touch the ground and receive damage, unless the plane is inverted or it is a high-energy crash (in which case there would be far more casualties). The wing tanks feed directly to the wing-mounted engines, so minimal fuel plumbing.
Looks like the left engine may be partially detached - probably the source of the leaks.
CBC has a story and photo. Plane not inverted. Left wing (at least) probably damaged, but still "in one piece." Still no fatalities.
All 25 passengers on crashed Saskatchewan flight 'accounted for' but some require air ambulance, RCMP say - Saskatoon - CBC News