A medical emergency on a flight headed from Los Angeles to Seattle on Thursday led to the death of a young girl onboard, who reportedly suffered a cardiac arrest.
The girl, who has not been named publicly, was 10 years old, according to CNN affiliate KTLA.
Delta flight 2423 “returned to Los Angeles International Airport shortly after takeoff due to a medical emergency onboard,” Delta said in a statement emailed to TIME. The airline noted that paramedics were called to respond to the situation, and that other passengers were put on alternate planes to continue toward their final destination.
The Los Angeles Fire Department said in a statement that paramedics “furiously worked to save [the girl’s] life” but that “all efforts were futile and the child was beyond medical help.” Her death was “determined on scene,” the LAFD said.
The fire department said that the Los Angeles Police Department would handle the child’s death investigation and the Los Angeles Coroner’s Office would determine the official cause of death. Neither agency immediately responded to TIME’s request for comment, though police officer Mike Lopez told CNN that the LAPD had determined there was no foul play involved.
The Federal Aviation Authority directed a request for comment to local authorities and Delta airlines.