HAYWARD, Calif.(AP) - A toddler slipped into his family's back yard in Hayward undetected, and drowned in the swimming pool. Investigators say the boy's parents found him in the pool Wednesday morning. Emergency crews rushed over and took the 19-month-old child to a Castro Valley hospital, but he was pronounced dead soon after he arrived. Police say it was a tragedy; the boy seems to have opened a back door and slipped into the yard while no one was looking. There was no fence around the pool. They are investigating the case as an accidental drowning. --- Information from: San Francisco Chronicle, http://www.sfgate.com/chronicle (Copyright 2009 by The Associated Press. All Rights Reserved.)