PG&E has given this home the all clear and the people who live upstairs are back inside, but obviously, this will be a morning they'll never forget.
Carbon monoxide is called the silent killer, but it was a loud detector that may have saved several lives this morning. It was going off at this home on Moultrie Street in the Bernal Heights neighborhood in San Francisco just before 4:30 this morning.
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One of the four people living in the upstairs unit called 9-1-1. They were evacuated and treated by paramedics at the scene. They were okay but downstairs, where an elderly couple lives, firefighters heard a television but no one answered the door.
"So we forced entry into the building where we immediately located the elderly female unconscious in the front door. She was given advanced life support care and transported to Saint Francis hospital which has a specialized, hyperbaric chamber, which is essential to treating carbon monoxide exposure," said Lt. Jonathan Baxter, SFFD spokesman.
Hospital officials say she is in stable condition.
There are now flowers outside the downstairs unit where the couple lived.
"It was a nice couple they were very old, staying inside," said neighbor Joost Van Son.
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The woman is currently in serious condition. Her husband was found in the bedroom, unconscious and without a pulse. Firefighters brought him out of the home and tried to save his life but he died at the scene.
"Tragic to watch him die pretty much," said Sarah Reichanadter, resident.
Reichanadter says the couple has lived at this home for a long time. PG&E shut off the gas and firefighters ventilated the home. Firefighters say the most likely cause of the carbon monoxide was the water heater. A carbon monoxide detector was also going off inside the downstairs unit but firefighters aren't sure why the couple didn't call 9-1-1 or leave their home.
RELATED: PG&E urges customers to schedule free appliance and carbon monoxide monitor checks
"The fire department was telling us that a lot of people don't have carbon monoxide monitors now so if you guys don't have them you should, you just never know, right?" said Reichanadter.
Firefighters recommend people to call PG&E and set up a free inspection of appliances in your home.
The home is split into 2 levels. Firefighters say carbon monoxide detectors were going off on both levels. pic.twitter.com/jbbPdWVDRw— Matt Keller (@MattKellerABC7) December 7, 2017
PG&E believes carbon monoxide came from heater or water heater in home on Moultrie Street in San Francisco. 1 dead, 5 treated for carbon monoxide poisoning. pic.twitter.com/yPTRFU8CX1— Matt Keller (@MattKellerABC7) December 7, 2017
One person is dead, another in the hospital and four treated at the scene for carbon monoxide poisoning at a San Francisco home on Moultrie Street. pic.twitter.com/8TpiJxnMeM— Matt Keller (@MattKellerABC7) December 7, 2017