From writer to writer, the only criticism I have is to describe the setting in more detail earlier. I was trying to imagine that he woke up in an abandoned shopping center from where he died. It's day time and he rushes topside of the shopping center as you said it was underground. Then he runs into a strip mall that's decaying and teaming with overgrowth everywhere. But then you changed the entire mental setting when you said it was night time and that he ignited an entirely different building from the second shot. So my only advice is to elaborate more on the setting as you introduce it. Other than that, great job.