Brownsville, TX – The Valley Star – Christmas turned tragic for a Brownsville elderly couple who police believe died of carbon monoxide poisoning over the weekend as they sought warmth from a gas heater.

According to Brownsville police, the bodies of Viviano Sierra, 78, and Evangelina Xagoraris, 73, were found Tuesday in the couple’s home on Portway Drive.

The cause of death has not been confirmed and autopsies have been ordered to determine carbon monoxide levels in the bodies, said Lt. James Paschall.

“The toxicology reports are going to be critical to determine the levels of poisoning,” he said.

Family members became worried after they hadn’t heard from the couple for at least two days and visited their home Tuesday afternoon, Paschall said.

The family noticed a strong gas odor surrounding the house and called 911 after repeated calls and knocks on the locked door went unanswered.

Emergency responders knocked down the door and found the deceased couple in their bedroom.Fire Marshall Ben Nuñez said his department will conduct tests to determine the origins of the gas.

“We’ll work with the gas company to run tests and determine if there were any leaks and where they are located,” Nunez said.

According to police, the last recorded carbon monoxide fatality in Brownsville occurred on July 8, 2002, when a teenage couple sought privacy in the garage of a vacant Brownsville house. They died of carbon monoxide poisoning after leaving the car’s air conditioner on and the garage door closed.

Santiago Navarro, director of the city’s building permits department, said there is no ordinance that requires carbon-monoxide detectors in homes. Such ordinances are prevalent in other regions where fireplaces and chimneys are commonly used due to extended periods of frigid weather.