Are we really THAT cruel?

During the last couple of days we have experienced numerous bush fires in Australia. The number of killed and hurt increases as the days goes by. Today 181 are confirmed dead, but the real numbers are higher.

Pursuant to the news the fires aren't innocent forest fires- they are caused by arsonists. By now to men are arrested, charged for arson. Is this some kind of chain reaction- when one lights the fire; others have to do the same? We experienced the same thing in California a few months ago. There as well, it was deemed as arson.
Because of these barbaric, horrible people towns are burned to the ground, families wiped out, effaced communities and destroyed forests. Due to heavy wind and hot temperature the firemen struggles to take control over the fire, and bad gets even worse. Australia has never experienced something like this, and as the situation is today it seems like it will never end.
The Australian Prime Minister said this was nothing else than a mass murder. There are no words to describe how terrible this is.