Answer:
During an earthquake, a house can be located on a section of the land that is forced downwards due to a fault. If the house is located on normal faults, the house would be located on the hanging wall. If the house was situated near reverse/thrust faults, the house would be on the footwall. As one of these "walls" is pushed against another during compression, one wall slips downward, resulting on any buildings "sinking" downwards.