An unfortunate example is the Northridge Meadows Apartment complex. Make certain that your contractor has consulted a structural engineer to address the specifics of your particular structure. If a major portion of your assets are in an unbolted home, this is something you need to think about. In most cases, for less than the cost of a paint job you can help protect your investment. 7.1 and greater - House could be nearing total loss.
Fire hazards develop.
If you have a raised foundation with poorly braced cripple studs, bolted or not bolted, the severity of the above damage scales would be greater and could occur in much lower magnitude quakes. Many emergency supplies could be damaged or contaminated. Authorities may not allow access to the supplies. Supplies may be destroyed by fire along with the home. The struggles with insurance collection and temporary housing.