That includes, for example, better anchoring roofs to walls, and walls to each other. Roofs can act like the top of a box, holding sides together during the twisting of shear forces. Without the top, sides of the box (or building) would more easily collapse. And in many unreinforced masonry buildings, walls and roofs are not tied together well.

"But most people don't do it because it is expensive," Welliver said in 2006.

He said upgrade costs are more manageable if people do retrofits at the same time they do other renovations, such as when replacing a roof. Many public school districts and Brigham Young University, for example, said they programmed seismic retrofits any time they renovated older buildings.

Some landmarks that were originally largely unreinforced masonry survived the 2008 quake because of seismic retrofits they received earlier, including the state Capitol, the Salt Lake City-County Building and the Tabernacle. Such buildings were essentially put on a system of shock absorbers to help them survive quakes.

Retrofits of other types of buildings also helped avoid some disasters. The University of Utah's Marriott Library was built on rigid welded columns that engineers figured would snap in a strong quake, resulting in the roof and walls pancaking down on students. Retrofits in 2006 added flexibility and survivability.

Such retrofits likely saved hundreds to thousands of lives during the 2008 quake and saved money in the long run. "Our feeling is that for every $1 you spend before (earthquakes for retrofits), it is worth $4 or $5 afterward," Carey said in 2006.

Bartlett and Welliver said in 2006 that if homeowners then wanted to know how safe their homes likely would be in earthquakes and whether they likely needed seismic updates, they could simply look at when they were built.

Building codes essentially did not have seismic considerations before 1975, so homes older than that likely did not have them either. Codes steadily improved through the 1980s and '90s with lessons learned from earthquakes elsewhere, so structures built then were considered progressively safer. The strictest and best codes were enacted in 2003, so buildings constructed after that were considered the safest.

Few Utahns insured

Most people who lost their homes in the 2008 quake were not insured for earthquake damage, and many are now financially ruined. Regular homeowners insurance does not cover quake damage, unless additional earthquake riders are purchased.

Most insurance companies estimated back in 2005 that only between 10 percent and 15 percent of their Utah clients then had earthquake insurance — though it varied from below 5 percent to 20 percent, depending on the location and company.