Television station KSAZ in Phoenix, Arizona, first reported that relatives of toddler Morgan Koepp confirmed she had been taken off life support just three days after being admitted to the hospital.
According to reports, Brianna Williams had left her daughter with her boyfriend for most of the day Sunday while she was out.
According to a GoFundMe page which has since been set up to help aid the child's medical expenses, Williams had tried to contact her 33-year-old partner all day, but was unable to get a hold of him.
Upon returning home, Williams reportedly noticed her daughter's face was swollen near her mouth and cheek.
KTKV reports Williams immediately took her daughter to the Phoenix Children's Hospital, where medical personnel found the young girl to be suffering from broken ribs and reported several bruises on her back and torso.
Hours after arriving at the hospital, Morgan was moved to the intensive care unit, where her heart failed, according to the GoFundMe.
Tim Williams, Morgan's grandfather, told the television station, 'She had cardiac arrest. They had to bring her back. She went into another cardiac arrest. They had to put a machine on her to keep her alive.'
Morgan underwent multiple surgeries, including one to remove what turned out to be a flesh-eating bacteria.
'It’s a necrotizing soft tissue infection that opened up when she got hit or punched or whatever she did, and it spread throughout her body,' Mr Williams explained.
A letter from the grieving mother to her daughter has since been posted to the GoFundMe account.
'To my beautiful baby girl who taught me so much in these last 3 years. I saw you fighting and fighting as hard as you could. I saw how much pain you were in and I am so sorry you had to endure such a tragedy,' the letter began.
'Its breaks my heart and to see you laying there fighting so hard for mommy shows me how much you tried and how much you love me. I hate that I will never be able to watch you grow and see you again or hold you again until I one day get to heaven. But I am able to keep going because I know you are now resting in a better place.'
The 33-year-old boyfriend has since been arrested on suspicion of child abuse, KTVK reports.
According to court documents, the man became 'frustrated' with Morgan after she had multiple bathroom accidents, but that he had not intended to cause harm.
'The defendant stated he held his hand over the victim's mouth when she was screaming during her diaper change,' KTVK reports the documents stating. 'The defendant stated he had to use force to hold the victim to change her diaper...The defendant stated her did not mean to cause the injuries but was frustrated.'
This article originally appeared on New Idea.