Police in Alhambra were investigating the death of a 25-year-old Cal State Los Angeles nursing student who was found unconscious at her home on Monday.
Monique Rivera was found unresponsive by her mother when she returned home from an afternoon shopping trip, the Alhambra Police Department stated in a news release.
Paramedics who responded to the home in the 3100 block of Norwich Avenue were unable to revive Rivera, according to the release. She was pronounced dead at the scene.
The family dog, a small poodle, was also found deceased.
There was no evidence of a struggle or forced entry at the home, according to police at the scene.
Investigators were looking into the possibility that a faulty water heater in the kitchen may not have been vented properly, causing carbon monoxide fumes to be released into the house.
In the wake of the incident, Alhambra police officials were encouraging residents to make sure they had working smoke and carbon monoxide detectors.