The Delaware Department of Justice says the three girls responsible are minors, but must be held accountable for their actions.
Investigators say 16-year-old Amy Joyner-Francis was assaulted by three teenage girls back on April 21st in a bathroom inside Howard High School of Technology in Wilmington, Delaware.
The medical examiner determined that Joyner-Francis died from a pre-existing heart condition with contributing factors.
According to the examiner's report, "Amy died from a cardiac incident that she was vulnerable to because of a pre-existing heart condition, but the cardiac incident would not have occurred if she had not been assaulted."
"At the end of the day, nothing brings Amy back," said Wilmington City Council member Sherry Dorsey Walker, speaking on behalf of Joyner-Francis' family. "So whatever the charges are, their issue is, Amy is never coming home."
Walker could not say if the family was aware of the condition.
"If, in fact, this proves she does have this cardiac issue, here's the concern: it would not have been triggered had she not been hit in the manner which she was," Dorsey Walker said.
Action News is not identifying the girls who are charged because they are minors.
Authorities said a 16-year-old girl, the only person believed to have struck Joyner-Francis, is charged with criminally negligent homicide, which is punishable by up to eight years in prison. Prosecutors said they will seek permission from Family Court to have the girl tried as an adult in state Superior Court.
The other two suspects, also 16, are charged with third-degree criminal conspiracy, which is punishable by up to a year in prison, they added. They will be tried in Family Court.
Authorities did not disclose a motive for the confrontation.
According to a police affidavit, a video of the assault obtained by investigators shows a girl striking Joyner-Francis repeatedly in the head and torso with what appears to be a closed fist. As the attacker leaves, Joyner-Francis then attempts to stand up.
"Witnesses confirm that Joyner-Francis then began exhibiting disorientation and collapsed shortly thereafter," the affidavit reads.
Authorities also said in court documents that written and oral communications among the three suspects indicate that the assault was planned over the course of the preceding 20 hours.
Chief state public defender Brendan O'Neill, whose office is representing one of the suspects charged with conspiracy, described the death of Joyner-Francis as "a terrible accident in the context of an ugly incident."
"It's a tragedy all the way around," he said. "The consequences are going to be life-changing for all the kids involved."
Wilmington Mayor Dennis Williams issued a statement saying the charges are a "first step" in providing the victim's family and the community with closure.
"As this process moves forward, I ask that we keep the family and loved ones of everyone involved in our thoughts and prayers," Williams said.
"Now their lives are completely destroyed, and for what?" said Walker. "A bathroom fight. Is it worth it?"