An eight-year-old girl named Sydney Weston lost her life aboard SkyWest Flight 5121 following a severe medical emergency, according to Daily Mail.

The flight had departed from Joplin, Missouri, on Thursday and was en route to Chicago. Approximately 45 minutes after takeoff, the flight was diverted to Peoria, Illinois.

According to officials, Sydney became ill and unresponsive mid-flight, prompting an emergency landing. “Her family immediately notified the flight personnel of her condition, and they began rapidly rendering aid,” stated the coroner.

Upon landing at General Wayne A. Downing Peoria International Airport, first responders found the girl unresponsive, without a pulse and not breathing.

Despite aggressive resuscitative efforts, Sydney was declared dead 2 hours after the flight at a local hospital. An autopsy is scheduled for Friday to determine the cause of death.

The Peoria County Coroner’s Office released the following statement:

The preliminary autopsy was inconclusive and pending several studies. However, there was no evidence of foul play and no signs of abuse or neglect.

We will be awaiting histology, biopsies, cultures, blood hematology and chemistry, and toxicology testing. These tests generally take 4-6 weeks to result. Once we have those tests completed, it is our hope that we will be able to provide a definitive and exact cause of death for this little girl and give her family some answers.

In reference to the below release on behalf of the Peoria County Sheriff’s Department:

The child, 8-year-old Sydney Weston, of Carl Junction, MO, was traveling with her family for vacation when she suddenly became ill and then unresponsive in flight. Her family immediately notified the flight personnel of her condition, and they began rapidly rendering aid. Upon landing in Peoria, she was not breathing and had no pulse. Deputies, AMT Personnel, and Air National Guard Fire personnel immediately began life-saving measures.

Little Weston was emergently transported to OSF Healthcare Saint Francis Medical Center in Peoria, where, despite aggressive resuscitative efforts, she was pronounced deceased at 8:05 am this morning.

An autopsy is scheduled for tomorrow, and this release will be updated with more following those preliminary findings.

SkyWest operates through partnerships with United, Delta Air Lines, American Airlines, and Alaska Airlines.

“We appreciate the efforts of our crewmembers who responded quickly to assist and the medical personnel who met the aircraft,” a SkyWest spokesperson told USA Today.