NEW WINDSOR — The evening a drunk driver struck and killed her son on Route 300, Sonia Borrero heard the sirens from her home.“Those sirens were for my son, who was left to die on the side of the road,” she said Friday. “How do you leave somebody like that? How do you leave a human being to die on the side of the road?”Borrero spoke at her home, on her birthday, to help state police with a simple message: Don’t drink and drive.