At Mo Bei City, at 20: 25 of 16th March, the fourth explosion occurred 18 hours and 7 minutes after its preceding explosion. This explosion caused the mutated area to expand double its previous size. From the satellite picture, the area had expanded from 30 cubic km to 70 cubic km. In other words, it easily engulfed the quarantine circle. This proved the futility of the quarantine circle.
The gap between the 4th and 3rd explosion was 80 percent slower than its predecessor and the expansion rate lowered from 10 times to only twice as big. The rate of expansion had conspicuously slowed but it was still growing. This meant that Phecda still could not let their guard down. Even if the expansion proceeded at this slower speed, it would destroy the whole district within half a month. Considering the mutated area was only 300 cubic metres less than 24 hours ago, looking from the big picture, the expansion was not slow at all. It was rapidly growing.