Updated at 10:17 p.m. ET: Forty-three students and six staffers at an Atlanta elementary school were rushed to the hospital early Monday after exposure to carbon monoxide fumes, fire officials told NBC News.

The students and staffers from Finch Elementary in southwest Atlanta exhibited mild and moderate symptoms related to carbon monoxide poisoning. Four more adults arrived at Grady Hospital by school bus, hospital spokeswoman Denise Simpson said.

The school was evacuated as a precaution, NBC affiliate WXIA reported.

The incident was first reported at about 8:35 a.m. ET, according to WXIA. No one was found unconscious at the scene, but the carbon monoxide reading was 1,700 parts per million, which an Atlanta Fire Rescue Department official said was high.

"Once we got inside, we started finding carbon monoxide readings way, way higher than we've ever experienced before, especially around the heating units and hallways, and the entire building turned out to be saturated," Atlanta fire Battalion Chief Todd Edwards told The Atlanta Journal-Constitution.

Edwards also told the Journal-Constitution the school apparently doesn't have carbon monoxide detectors. However, state law does not require schools to have CO detectors, a spokesman for Georgia’s Insurance and Safety Fire Commissioner told the newspaper.

Carbon monoxide is an odorless, colorless gas that can cause sudden illness and death, according to the Centers for Disease Control and Prevention. The most common symptoms of carbon monoxide poisoning are headache, dizziness, weakness, nausea, vomiting, chest pain and confusion.

Erik S. Lesser / EPA

Students are evacuated from Finch Elementary School by members of the Atlanta Fire Department in Atlanta, Dec. 3, 2012. Almost 50 people were reportedly taken to the hospital for treatment following a carbon monoxide leak.

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A carbon monoxide leak believed to be from a malfunctioning heating and ventilation system sent 49 female inmates to hospitals from York County Prison in Pennsylvania, authorities said Thursday.

The illnesses began about 11 p.m. Wednesday in a female dormitory housing about 90 women, the York Daily Record newspaper reported on its website. By early Thursday, 49 inmates had been taken to hospitals. All the inmates had been returned to the prison by Thursday afternoon, the county said in a statement, according to the newspaper.

The heating system was shut down, and the county's statement said carbon monoxide levels had returned to normal.

Prison Warden Mary Sabol said prison officials would meet with the McClure Co., the company that works on heating at the prison, and would consider installation of carbon monoxide detectors, the Daily Record reported.

About 215 women are incarcerated at the facility, 85 miles west of Philadelphia.

Prisoners living in the affected unit have been relocated to other areas in the facility.

This article includes reporting by The Associated Press.

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Jonathan Sanger / NBC News

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.

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“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.”

The storm boasted wind gusts of more than 50 mph and dropped heavy snow on already-weakened tree limbs, leading to the new outages. 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. 

Record snow, new power outages as storm slams Northeast

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.

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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."

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NBCWashington.com

Emergency crews investigate the apparent carbon monixide poisoning of five people in Oxon Hill, Md.

Updated at 1:15 p.m. EDT: Five people died Tuesday morning from apparent carbon monoxide poisoning in Oxon Hill, Md., Prince George's County officials told NBCWashington.com.

Firefighters said they found four men and one woman in the Shelby Drive home.

A family member became concerned when he called the home and no one picked up, so he visited the home around 10:45 a.m. EDT. He called 911 after finding two unconscious men near the entrance of the home, said Mark Brady, chief spokesperson of Prince George's County Fire and EMS.

See the original story at NBCWashington.com

Rescue workers tried to revive those two men, but when others went further into the home, they found three more unconscious people in various rooms.

Brady said he believes they are all members of one family, but he’s not positive. Three of the men were in their 30s and one was in his 40s. The woman was in her 60s.

The family was from El Salvador, NBCWashington.com reported.

At a 1 p.m. news conference, fire officials said they found the house’s heating system was in disrepair. The furnace’s exhaust pipe was rusted and separated, officials said.

Also, the home had no carbon monoxide detector, which could have prevented the deaths, they said.

See carbon monoxide safety tips

The home's carbon monoxide levels were "extremely high" at about 550 parts per million, Brady said. Normal levels are 0 to 5 parts per million, he said.

The one-story single family home is about 1,900 square feet, and in a small home, the gas would have built up quickly.

"At that high a level of CO... it would not take them long to be overcome and suffer fatal injuries," Brady said.

They are currently unable to locate the source of the carbon monoxide, but are looking at the furnace and stove. Officials from Washington Gas Company are on the scene.

“We have been through this neighborhood several times, passing out information about CO and warning people of the dangers of CO,” Brady said. “This is not our first time being in the South Lawn neighborhood."

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