TYLER-- Ava Faith Ayers turned two today.  Ava's 16-year-old babysitter was watching the girl and her three-year-old sister.  Around 2:00 this afternoon, while the babysitter was talking to someone, police say Ava went outside, where she fell into the swimming pool.  Ava was taken to a local hospital, but doctors could not revive her.  The case is still under investigation.