House foundation failures can be caused by a lot of things including:
1. Settling into bad soil
2. Frost heaving due to inadequate depth below frost line
3. Water pressure from the outside or under the foundation
4. Weakening of the soil due to saturation
5. Large tree roots applying pressure against the foundation wall
6. External soil loads such as from a heavy load near the foundation
7. Subsidance of the soil from pumping water or mining
8. Changes in the supporting structure
9. Inadeqaute design for the loads
10. Changes in loads
11. Nearby blasting
13. Unknown unknowns
14. Some that I haven't thought of
You may send pictures. I have a high speed connection and accept EMail. Photos of the cracks with a ruler in the photos or other means to show dimensions, and photos of the house from all sides but especially on the sides corresponding to the location of the failures, would help to get you pointed in the right direction.
Describe when the failures were first observed, and the time relative to any changes in the neighborhood or grading or modifications to the house.
One quick way to fail a foundation wall is to bring a Ready-Mix concrete truck too close to the foundation.