A total of 11 people have been transported to the hospital for examination following a possible carbon monoxide poisoning incident Sunday night, according to a San Francisco Fire Department dispatcher.
The incident at 1223 Cortland St. was reported at 7 p.m. after a carbon monoxide detector sounded in the top apartment of a Bernal Heights duplex, the dispatcher said.
Eight adults and three children were evacuated from the building.
The patients had some carbon monoxide in their bloodstream and some residents experienced symptoms of carbon monoxide exposure such as headache and scratchy throat.
No word yet on the cause of the carbon monoxide leak. The Chronicle has the same story, only they report 14 victims were hospitalized.
UPDATE: The Chronicle adds additional information which suggests there may be less to this incident than meets the eye:
Fourteen partygoers were taken to the hospital late Sunday in San Francisco’s Bernal Heights neighborhood after complaining of carbon monoxide poisoning, authorities said.
But only two people tested positive for having low levels of the deadly gas in their blood and no leak was found in the duplex unit at 1223 Cortland Avenue, said Mindy Talmadge, a fire department spokeswoman.
Firefighters arrived on scene at 7 p.m. and found 14 people outside the empty house and a blaring smoke alarm inside, Talmadge said.
The revelers complained of scratchy throats and were tested at the scene for carbon monoxide poisoning, Talmadge said. Only two people, one an elderly smoker, tested positive for the gas.
“There can be other reasons for CO readings in your blood – heavy smoking” Talmadge said. “There was evidence of a lot of cigarette smoking in the unit.”
The remaining 12 people may have suffered from psychosomatic symptoms, but were still taken to the hospital for evaluation, Talmadge said.
“I am not saying this is it, but sometimes when something is mentioned, people start thinking ‘My throat is a little scratchy,'” Talmadge said.
Firefighters, public health officers and Pacific Gas and Electric Co. workers spent four hours combing the house, but were unable to find any sign of carbon monoxide gas, Talmadge said.
The SF Appeal calls the whole thing a “false alarm.”
PHOTO: 1223 Cortland via Google Maps
Bernalwood 
Thank goodness the had a CO detector. We have friends whose entire family came very close to dying because of a late-night CO leak in their home while they were sleeping.
14 people live in this house?!
ah turns out it was mostly partygoers: http://www.sfgate.com/bayarea/article/S-F-partygoers-cleared-of-CO-poisoning-4067370.php