(Updated 10:11-a.m.) DES MOINES, Iowa (AP) — A Mexican official says autopsies show the gas that killed an Iowa family was propane that leaked from a faulty water heater at their rented condominium in Mexico. Investigator Christopher Martinez with the attorney general’s office for the state of Quintana Roo told The Des Moines Register on Wednesday that the water heater had rusted in the humid climate.

Services were held Saturday in Creston for 41-year-old Kevin Sharp and his wife, 38-year-old Amy Sharp, and their children, 12-year-old Sterling and 7-year-old Adrianna. Their bodies were found March 23 inside the condo in the resort town of Tulum. Amy Sharp’s cousin Jana Weland said Wednesday that relatives know the water heater was the suspected source but that U.S. and Mexican officials hadn’t yet said what type of gas the Sharps inhaled.

The condo association has said owners are responsible for maintenance. The water heater was bought in 2012, Martinez said, and its warranty ran out last year. He wouldn’t say who owns the condo. The family’s rented car was full of sand the day bodies were found, leading police to believe the Sharps had been at the beach the day they died. Investigators think the family returned to the condo to bathe and rest.