Actually, Salt Lake County is now essentially divided into six parts — a worst-case scenario that Carey said in 2006 was possible — and crossing between them will not be easy for emergency responders and others.

The sections include the area east of the new, higher Wasatch fault scarp; west of there to the Jordan River; west of the river to the new Taylorsville fault scarp; between it and the new Granger Fault scarp; and the area west of that to the Oquirrh Mountains.

Also, Salt Lake and Davis counties are essentially cut off from each other because of failure of some older freeway bridges — which the state had planned to replace soon — and damage and fires at oil refineries at the border of the two counties.

All this damage has happened in under a minute.

People near the Wasatch fault itself felt the worst of the shaking for only 10 to 15 seconds. Utah Geological Survey maps in 2002 said the most severe of all shaking would be in those areas near the main fault.

But deep, loose sedimentary soils on the "valley side" of the fault actually amplified ground shaking in some areas, and made residents there feel it longer — about 20 to 30 seconds, with some reverberations felt for up to 50 seconds after the rupture.

Robert Archuletta, a seismology professor at the University of California at Santa Barbara, was one who predicted in 2006 that the overall worst ground shaking would happen in areas over such deep soil on the valley floor — where a huge segment of the Salt Lake Valley population lives.

"The strongest shaking will be about 1 to 4 kilometers (up to about 2.5 miles) from the (Wasatch) fault . . . , roughly to about where I-15 is," Archuletta said in a 2006 presentation. "As a consequence, the ground motion is strongest where the people are."

A damage snapshot

A quick snapshot shows some of the monumental destruction that faces the area, or soon will. The extensive damage is hit-and-miss — like the impact of a tornado hitting one house and missing a neighboring one — because of differences in soil and geology in different areas, and also in construction methods used.

But about 6,200 people are dead. Carey, with state emergency services, said in 2006 that such a quake could kill between 2,200 and 6,200 — and the worst-case has occurred.

Sadly, more than 700 students and teachers were killed at schools, and 13,000 more were injured there.

More than 90,000 people total are injured in the quake area.