Twin 3-year-old girls drowned in their family's backyard pool in Phoenix despite their dad's desperate efforts to revive them.

Firefighters raced to the home and arrived in less than three minutes after getting a 911 call around 3:30 p.m. Thursday, local TV station ABC15 reported.

"We had a father on scene attempting to do  CPR on both children," Phoenix Fire Capt. Rob McDade told reporters after the tragedy. "You can imagine what that would look like and how taxing that would be."

The toddlers were rushed to a nearby hospital where they were pronounced dead.

On Friday, police identified the little girls as Valentina and Penelope Ruiz. Detectives are continuing to investigate.

"Preliminary information suggests that this incident is consistent with an accidental drowning," police Sgt. Rob Scherer said in a statement. "At this time, there is nothing that investigators have found that appears suspicious.