There is particular cause for concern in regions which can generate strong earthquakes , but only rarely . Such regions may not have regulations limiting the construction of UMBs , or have only implemented them recently . Public awareness of earthquake safety may be low . For example , the Wasatch Fault in the U.S. state of Utah closely parallels the state 's most populous metropolitan area , the Wasatch Front ( which includes the state capital Salt Lake City ) . The Wasatch Front has a population of 2 million , and contains 200,000 UMBs compared with the entire state of California 's 25,000 . Utah has recently retrofitted many public UMBs to better withstand earthquakes , but most UMBs in the state are private homes . The lack of earthquake codes preventing the construction of UMBs was a major factor in the high death toll in the 2010 Haiti earthquake
2010 Haiti earthquake
2010 Haiti earthquake
Unreinforced masonry building