The 22-month-old girl was declared brain dead, three days after her father returned from his university teaching job to find her barely breathing.
The child, called Elena, had surgery to relieve swelling on the brain, but doctors at the Salesi pediatric hospital in Ancona, Italy, said it was too extensive to save her. An autopsy is planned for Tuesday.
Dr. Francesca De Pace, coordinator for transplants in the Ancona area, expressed gratitude to the parents for giving permission for Elena's heart, liver and kidneys to be transplanted.
"If people stop and reflect, this might be the only consolation, the donation of organs, the only thing that might give some sense to this tragedy," De Pace told a news conference.
Officials said a 2-year-old boy in a Bergamo hospital received Elena's heart, while the liver recipient was a young boy in Turin. The kidneys were being checked to see if they were suitable for transplant.
Prosecutors will decide whether to charge the father, Lucio Petrizzi, with manslaughter.
The distraught Petrizzi has told investigators his memory went blank and that he inexplicably thought he had dropped the child off at nursery on his way to his job as professor of veterinary medicine at Teramo university, as was his routine. When he found the child after finishing teaching, he frantically called for an ambulance.
The child's mother, Chiara Sciarrini, fighting back tears as she read a message on television Saturday, appealed for understanding for her partner, whom she described as being distracted while juggling many responsibilities.
"I want to shout to the entire world how much my companion loved his daughter, he is an exemplary father," said Sciarrini, a university researcher who is eight months pregnant. "What happened to him could happen to anyone."
She said Petrizzi was "worried about me, about my pregnancy and about little Elena."
"Everything was supposed to be perfect and I wasn't supposed to worry," she said, sorrowfully. "He was supposed to bring Elena to day-care and I was supposed to stay home and rest," Sciarrini said, adding "his little girl adored him."
What an unimaginable tragedy.