It's based on a true story.
There actually is a city called Phoenix.
sharelol..but actually they based their monster story on this
https://en.wikipedia.org/wiki/Phoenix_Lights
that's the spooky part
Yeah... because of a temperature inversion layer and unusually clear skies allowed a superior mirage of an A-10 Warthog dropping flares during training to be seen hundreds of miles away in Phoenix by a bunch of people who had no idea what they were looking at.... And a bunch of total morons jumped on the "Its aliens!" bandwagon....
Yeah... scary.
I joined the Navy to see the world, only to discover the world is 2/3 water!