TUCSON- Police say an 18-month-old Tucson boy died when he fell headfirst into a small cooler filled with ice and water while his father slept.

Nicolas Claus was found just before noon Tuesday when his father awoke and went looking for him. Tucson police Sgt. Mark Robinson says it appears the boy couldn't get out of the 18-inch-square beer cooler.

Robinson says the toddler's 22-year-old father works nights and the grandmother usually watches Nicolas while the father sleeps. But Tuesday morning, the father took the grandmother to the airport, came home and fell asleep.

Police haven't identified the father, but say he immediately began lifesaving efforts and called out to two passers-by for help.

Robinson says no charges have been filed against the father.