An Amazon delivery driver has died after she was found unresponsive inside her van at a Florida delivery stop, sparking an investigation into the mysterious circumstances surrounding her death.

The unidentified woman was discovered inside the Amazon delivery van in Lake County on Monday, Aug. 10, after a concerned neighbor noticed the vehicle had been sitting outside a home for roughly four hours.

The neighbor eventually called authorities to request a welfare check.

“I’m just looking to report a wellness check, I guess? Or to report an abandoned vehicle,” the caller said, according to WESH 2.

Lake County Sheriff’s Office deputies responded to the scene at around 7:22 p.m. and found the woman unresponsive inside the vehicle.

Lake County Fire Rescue and EMS immediately attempted life-saving measures before rushing her to a nearby hospital.

She was later pronounced dead.

But the troubling scene reportedly took another turn when a neighbor claimed the officer who removed the woman from the van began coughing.

Patrick Miranda, who witnessed the emergency response, told WESH that authorities appeared concerned about possible fumes inside the vehicle.

“They pulled her further away from the vehicle and then fire utilized a hose to rinse down the person,” Miranda said.

Authorities have not announced whether fumes or any other hazardous substance played a role in the woman’s death.

Her official cause of death has not been released, and her identity has also been withheld from the public.

Amazon confirmed the woman worked as a delivery driver for the company and said it is cooperating with investigators.

“We’re deeply saddened by this tragic incident, and our thoughts and prayers are with the driver’s loved ones during this difficult time,” Amazon said in a statement. “We’re cooperating fully with local authorities in their investigation.”

The Lake County Sheriff’s Office continues to investigate what happened inside the van and what may have caused the driver to suddenly become unresponsive.

For now, the circumstances surrounding her death remain a mystery.