March 25 (UPI) -- An Iowa family of four that was found dead at a vacation condominium in Tulum, Mexico, died from gas asphyxiation, Mexican authorities said.
The Quintana Roo state prosecutor's office said Saturday autopsies revealed Kevin Wayne Sharp; his wife, Amy Marie Sharp; their son, Sterling, 12; and daughter Adrianna, 7, all died after inhaling toxic gas.
Authorities didn't specify where the gas came from but ruled out the possibility of foul play.
"Any violent act or suicide has been discounted," Mexican authorities said.
The family had been dead for 36 to 48 hours when their bodies were discovered on Friday, the prosecutor's office said.
Mexican officials performed a "physical inspection of the room's gas installation" after the discovery and are expected to release a technical report.
Authorities found the bodies of the parents in a bed and those of the children in front of a television during a welfare checkn Friday.
The family arrived in Tulum on March 15 and had been staying in a house they found through a vacation rental company.
They were expected to return from their vacation Wednesday and extended family members reported them missing to local police, who contacted the U.S. State Department, after initially suspecting they had missed their flight home.