8-year-old girl has medical emergency on SkyWest flight to Chicago and dies

An 8-year-old girl from Missouri became “ill and unresponsive” on a SkyWest flight to Chicago on Thursday and was later pronounced dead, authorities said.

The flight took off from Joplin, Missouri, and was headed to Chicago before making an emergency landing in Peoria, Illinois.

“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,” according to a statement from the Peoria County Coroner’s Office.

The child was identified as Sydney Weston, of Carl Junction, Missouri, the coroner's office said.

The plane landed at the General Wayne A. Downing Peoria International Airport about 7 a.m. because of a medical emergency, the Peoria County Sheriff’s Office said Thursday on Facebook.

Emergency personnel, including deputies and the Air National Guard, attempted “life-saving measures,” but the child was later pronounced dead at a local hospital, the sheriff’s office said.

SkyWest Airlines on Friday confirmed that the child was aboard flight 5121, operating as United Express, from Joplin to Chicago O'Hare International Airport, when a passenger became sick and the flight was diverted to Peoria.

There, she was "met by paramedics to attend to a passenger in medical distress. We appreciate the efforts of our crew members who responded quickly to assist and the medical personnel who met the aircraft," SkyWest said.

The girl died shortly after 8 a.m., the coroner’s office said.

“There was no evidence of foul play and no signs of abuse or neglect,” the coroner’s office said in a statement Friday.

But a preliminary autopsy was inconclusive "and pending several studies," it said.

Medical personnel is awaiting histology, biopsies, cultures, blood hematology and chemistry, and toxicology testing. Results generally take four to six weeks.

"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," according to the coroner's office.

The family of Sydney Weston could not be immediately reached Friday for comment.

Antonio Planas

Antonio Planas is a breaking news reporter for NBC News Digital.

Madelyn Urabe contributed.