Officers arrived at the home in the Tulare County town of Lindsay. The home is located on Westwood and Mariposa.
Lindsay Police left this area around 10:00 p.m., but they spent the entire day and night trying to figure out how the toddler sustained such serious injuries.
The little girl is now in a Bay Area hospital fighting for her life after being transferred from a local hospital.
Lindsay investigators collected evidence in and around this home Thursday night.
Police say a babysitter who is a family member called 911 just before 11 a.m. claiming that a two year old girl was unresponsive.
Medics used CPR to revive the toddler who was rushed to Sierra View hospital.
Police Chief Rich Wilkinson says they're taking no chances with this case.
"When you have a critical or serious injury to a child, you don't want to dismiss the seriousness or the simply write it off as an accident." said Wilkinson.
Investigators questioned the male babysitter and the two-year-old girl's parents who were at work and not at the home at the time of the incident.
Police say what makes this case challenging is that the toddler showed no signs of physical trauma, making it difficult to determine how she suffered the injuries.
"It's a puzzle in which we want to put together all the pieces to ensure that there was no foul play. That there was no intent on injuring the child and we're still in that process now." added Wilkinson.
Medics airlifted the two-year-old toddler to a Bay Area hospital around 7:45 p.m. for treatment. We're told her parents are driving from Lindsay to the Bay Area as to be with their daughter.
No charges have been filed against the babysitter at this time. Investigators are working with the sheriff's department to get back forensic results they hope will answer some the questions at the home.