A 3-year-old girl died, and a 4-year-old boy is recovering after both got into swimming pools over the weekend.
The girl was found in the pool of a home northwest of Tucson late Saturday.
She and her parents were among several people at a backyard gathering in the 8200 block of North Equator Loop, near North Oldfather and West Cortaro Farms roads, said Capt. Adam Goldberg, a spokesman for Northwest Fire District.
The call to 911 came in at 11:43 p.m. after the girl was pulled from the pool. Bystanders started CPR, and an emergency crew arrived within four minutes.
The girl was taken to a hospital, where she died.
There was no barrier around the pool, and the girl was last seen about 15 minutes before she was spotted in the water, Goldberg said.
The Pima County Sheriff's Department investigated the incident and called it a "tragic" accident, said Deputy Tom Peine, a spokesman for the department.
He said Sunday that homicide detectives said there was no criminal act that led to the drowning.
The drowning occurred the same day as a near drowning on Tucson's east side.
The 4-year-old boy nearly drowned at an apartment complex swimming pool.
A resident of the complex in the 6100 block of East Pima Street called 911 at about 6 p.m. Fire crews arrived to find the child with blue skin, coughing and crying, officials said.
The boy was likely underwater for about a minute, officials estimated.
Capt. Jeff Langejans said Sunday the boy was "conscious and breathing on his own."