ACAPULCO, Mexico (AP) _ The bodies of four family members were found Monday in a foul-smelling well, the apparent victims of asphyxiation from methane gas.

One of the victims, 33-year-old Saturnino Dominguez, apparently was trying to clean out the artesian well next to his house in the coastal town of Azoyu when he was overcome by methane fumes, said state civil protection authority Marcos Gonzalez.

When his wife, Francisca Martinez, 19, found him unconscious, she tried to rescue him, but was asphyxiated as well. Martinez's brother, 18-year-old Ricardo Ramirez, and a nephew of the couple, 19-year-old Ciro Roque also died when they tried to rescue the couple, Gonzalez said.

Gonzalez said officials from the state-owned gas company Pemex are also investigating whether there was any possibility that gasoline could have leaked from tanks at a gas station 500 feet from the house.

Pemex officials told authorities they had just conducted an inspection of the gas station last week and did not find any leaks.

Civil protection and local authorities were conducting tests to determine what types of gases were emanating from the well and what risks they presented.

Authorities also planned to conduct an autopsy on the bodies. There were no signs of violence or foul play, however, Gonzalez said.