WEST ISLIP - A West Islip teen is using a personal tragedy to spread a message of love to thousands of others. Fifteen-year-old Brooke DiPalma's father took his own life last year. The retired NYPD officer left a postcard for his daughter that said just three words: "I love you." DiPalma says she wants to save lives so that other familes don't have to cope with such tragedies. She's spreading a message of love at school, on Facebook and in her YouTube video, which got 30,000 hits this month alone.With the help of friends, she created a 'P.S. I Love You Day' at school. The teens put Post-it notes all over the building to let others know they are loved. DiPalma says she's encouraging everyone in the community to wear purple tomorrow in honor of 'P.S. I Love You' day.