question:  Why would the band of scientists fear that there might not be pieces to pick up once the affected area population returned?
context: It has happened a hundred times in the long history of Earth—and, sooner or later, will happen again! Only Joseph Schwartzberg, head geographer of the Department of the Interior, wondered if the disturbance might not be a settling of the Kiowa Fault. The idea was not nearly so exciting as a volcano, even a lava-less one, and you couldn't draw a very dramatic picture of it. To excuse the other geologists, it must be said that the Kiowa Fault had never acted up before. The dust volcano was on the face of it a more plausible theory. As the tremors grew bigger, along with the affected area, as several towns including Edison were shaken to pieces by incredible earthquakes, whole bus- and plane-loads of geologists set out for Colorado, without even waiting for their university and government department to approve budgets. They found themselves on the scene of what was fast becoming the most violent and widespread earthquake North America—probably the world—has ever seen in historic times. To describe it in the simplest terms, land east of the Fault was settling, and at a precipitous rate. East, where sharp reports and muffled wheezes told of continued buckling and dropping, the earth trembled downward. Atop the new cliffs, which seemed to grow by sudden inches from heaving rubble, dry earth fissured and trembled, sliding acres at a time to fall, smoking, into the bucking, heaving bottom of the depression. Dry earth churned like mud, and rock shards weighing tons bumped and rolled about like pebbles as they shivered and cracked into pebbles themselves. But the band of scientists who had rallied to his leadership privately wondered if there would be any pieces. Land west of the Fault was holding firm, though Denver had recorded several small tremors; everywhere east of the Fault, to almost twenty miles away, the now-familiar lurch and steady fall had already sent several thousand Coloradans scurrying for safety. As the Fault moved north and south, new areas quivered into unwelcome life.
output:  The damage would be too substantial and there would nothing left to salvage.
options:  They were doubting the theory by Schwartzberg.  The damage would be too substantial and there would nothing left to salvage.  They feared that no one would escape alive.  Theft in the area was also on the rise.