As a child, Kevin Reilly was happy-go-lucky and industrious, and if he ever took a shortcut, his mother put a stop to it. In grade school, he was assigned a book report on "Robinson Crusoe." His mother, Joan, asked if she could see it. She found it suspiciously skimpy, and said, "Well, what about Friday?" And he said, "No, Mom, the report is due tomorrow, Thursday." "I think the only thing he read was the jacket," she said, laughing. His father, George, had been a firefighter, and though Kevin first worked as a hydrogeologist, he ended up following his father's career. He was assigned to Ladder Company 40 in Harlem, where his father worked for many years, but was on rotation to Engine Company 207 in Brooklyn. Known for his generosity, Firefighter Reilly was the first to buy a round of drinks and always wanted to pick up the check when he went to a restaurant for dinner with friends. Last July, at 28, he married his high school girlfriend, Jennifer Mulderrig. They lived in Manhattan. In their first year of college, he told her that he was going to become a firefighter, she was going to become a teacher and they were going to marry. She laughed at how he had it all figured out, especially since she had no particular interest in becoming a teacher. But that's how it turned out.