LUBBOCK, Texas– One person is dead and another was transported to the hospital after reports of carbon monoxide poisoning in a Lubbock home on Thursday.

At approximately 9:00 a.m., Lubbock Fire Rescue responded to the incident in the 3100 block of 3rd Street. Police and EMS also responded.

According to LFR, someone came to the home and found both parents unresponsive. One of the parents was able to wake up and was taken to a hospital.

LFR later confirmed that the other parent was dead, and there were no other updates on the parent taken to the hospital.

The cause of death will be determined by the Medical Examiner, according to LFR.

The residents were using a wall heater unit and also had their gas stove burners lit. LFR said there were high levels of carbon monoxide found inside the home, and the house did not have a carbon monoxide detector.

Family members of the couple in the house told reporters that when they went to check on them, they could immediately smell smoke, which got stronger as they went further into the home.

The case remained under investigation Wednesday by the Fire Marshal’s Office.

LFR and Atmos Energy said they see gas leaks and carbon monoxide cases increase every year during the winter season and urged people to refrain from using stoves, as well as appliances like outdoor grills, to warm homes. Instead, they suggested using space heaters or electrical heaters, and they asked everyone to get their heating appliances checked regularly as well as install carbon monoxide detectors.

The call initially was reported as a gas leak. After officials responded and learned more information, they determined it was a situation with carbon monoxide.