Drones buzz overhead, troops hunker underground in Ukraine's hellish Kill Zone

Ukrainian military medics treat a wounded Ukrainian soldier in the field hospital near the frontline in the southeastern reigion of Zaporizhzhia on Sept. 12. The vast majority of casualties take place in the so-called Kill Zone, a band about 10 to 20 miles wide on both sides of the frontline, which stretches more than 700 miles from north to south.

The frontline in the Russia-Ukraine war stretches more than 700 miles and has barely moved in four years. Yet straddling this line is the Kill Zone, dominated by constantly evolving drone technology.

(Image credit: Andriy Andriyenko/Ukrainian 65th Mechanized brigade)