ISLIP - Cops say a trip to the library ended with an unexpected plunge into the pool for a Suffolk County family.According to police the 35-year-old driver of an SUV was trying to park at the Islip library yesterday evening but accidentally hit the gas pedal instead of the brake. The unidentified woman drove right through someone's fence and ended up in their pool. The woman, her mother and two children all got out of the SUV safely.