A spa worker whose dead body was found at Las Vegas cryotherapy center last month after 10 hours in a chamber chilled by liquid nitrogen suffocated accidentally, the Associated Press reports. The Clark County coroner’s office said that she died from asphyxia caused by low oxygen levels.

Chelsea Patricia Ake-Salvacion, 24, was found on October 20 at the spa where she worked, having apparently gotten into the cryotherapy chamber after hours the night before. She died in an “oxygen-poor environment,” the coroner’s office said.

According to the AP, air is normally about 21 percent oxygen. Oxygen levels in the chambers used in cryotherapy—which involves brief exposure to extremely low temperatures (minus-166 to minus-319 degrees Fahrenheit)—can drop to less than 5 percent. “Breathing air with this low level of oxygen can quickly result in unconsciousness and then death,” said the coroner.

Las Vegas police say no crime is suspected in Ake-Salvacion, and State Occupational Safety and Health investigators have said that she should have not been using the chamber by herself. Ake-Salvacion’s family, however, have said that the young woman did not make any mistakes in operating the machine. The family’s lawyer, Richard Harris, said Ake-Salvacion had texted a friend about a possible nitrogen leak in the machine.

“Accidental death from an oxygen poor environment raises more questions than it answers,” Harris said in a statement. “Chelsea died from breathing poisonous liquid nitrogen produced from a cryotherapy chamber touted for its health benefits.”

Cryotherapy, which has not been approved for medical use by the U.S. Food and Drug administration, is widely unregulated and is currently subject to a broad investigation by the Nevada health department.

Image via News 3LV. Contact the author of this post: brendan.oconnor@gawker.com.