Sandy's silent killer: Carbon monoxide claims another victim Heather Humphries fills a generator with gas in Brooklyn, N.Y., on Saturday, Nov. 3, 2012. A Long Island, N.Y., woman died this week when a portable generator she began using after Superstorm Sandy knocked out the electricity in her neighborhood emitted fatal levels of carbon monoxide. Michelle Bracco, 44, was discovered unconscious in her home around 10 p.m. Monday, police said. She was taken to South Nassau Communities Hospital in Oceanside, N.Y., where she was pronounced dead, NBCNewYork reported. Police said a portable generator in the garage was being used to provide power to Bracco's home. Bracco's death wasn't the first caused by Sandy's silent killer since the storm passed. Local news outlets have reported that carbon monoxide poisoning has sickened dozens of people in more than 10 Northeast states in Sandy's wake. Now, as newly powerless residents throughout the storm-struck region crank up generators after a nor'easter brought record early snow and winter weather, the potential for more deaths is high, officials warn. "The stories that we're hearing over the last couple of days are frightening," New Jersey Poison Control Center Director Dr. Steven Marcus told NJ.com. People are just not thinking, and I'm afraid that the longer there is no power, the worse this could be. When combined with the residual outages left by Sandy, officials estimate some 700,000 are without power across the Northeast, according to utility providers in the region. Experts say carbon monoxide poisonings tend to spike when an area loses electricity because people often put power generators in partially opened or closed garages or bring charcoal grills indoors. Carbon monoxide can also seep through slightly open windows. Police blamed carbon monoxide for the death of James Stapleford, 75, and Eva Stapleford, 73, of Shokan, N.Y., who were using a generator to power their home in the wake of Superstorm Sandy, the New York Daily News reported. Police said the couple, who were discovered Monday, appeared to have been dead for two days. In Newark, N.J., Mudiwa Benson and Kenya Barber, both 19, died last week, police said, from prolonged exposure to carbon monoxide because a generator was too close to their apartment home, NJ.com reported. In Pennsylvania, four people died of carbon monoxide poisoning last week from generator fumes in separate incidents, the AP reported. And in Edison Township, N.J., a 65-year-old man likely died of carbon monoxide poisoning after running his generator in his garage last Wednesday, police said. When emergency medical services responded to his house, police said they found him "blue in color." The generator found in his closed garage had run out of gas, NJ.com reported. Carbon monoxide is completely odorless and invisible. Symptoms of poisoning caused by the gas include nausea, headaches, dizziness and vomiting, which can escalate to unconsciousness and death, according to the Centers for Disease Control and Prevention. The CDC advises placing generators at least 20 feet away from homes, since there's not enough ventilation within garages and basements or near open windows to prevent fatal poisoning. Battery-powered alarms are also necessary to warn residents before carbon monoxide reaches dangerous levels. Marcus said people shouldn't hesitate if they think they have a carbon monoxide problem. "They need to get out of the house," he said. Don't open the windows. Just get out of the house. Don't waste any time and get medical help.