The blocks weighed dozens of tons each and consisted of upright pillars and crossbeams that once formed the entrance to the structure.

What started as a calm Sunday drive turned into anything but when a glance into his review mirror left Casey Curtis shocked.

By precise numbers, it has reduced the average carbon content in the desert air from 416 parts per million to 413 ppm.

Crews had to break through concrete and dig through several feet of soil to reach baffle box," the structure where he had become trapped ...