The Cascade : A New End

It has been said time and time again. Mankind are like cockroaches. And in the opinion of one Bruno Estralez, is a correct and unfortunate fact.  But the days of war are far behind him. After some time from that event, he managed to secure a scholarship to an institution in Leipzig, Germany. Life was going great. Until the Second Cascade came. Now comes the questions; Who caused the Second Cascade and Why?